History of the Apple iMac

Introduction

Apple’s iMac first appeared in 1998 as an all‑in‑one desktop computer, and since then it has continued to evolve in design and technical specifications, remaining on sale to the present day as a long‑running product. The first iMac became the spark that revitalized Apple, which was then in a management crisis, and each subsequent generation has influenced the industry with advanced design and features. This report covers everything from the background of the iMac’s birth to a detailed account of each model generation, user reception and reactions, and a chronology of past models, providing a clear, logical history of the iMac.

Background of Development and the First Model

In the mid‑1990s, Apple was facing poor performance and a declining market share. Under then‑CEO Gil Amelio, next‑generation OS development was floundering, and Apple, driven to the brink, acquired NeXT in 1996 and brought back co‑founder Steve Jobs. In 1997, Jobs became interim CEO and boldly reorganized a bloated product lineup into four categories—notebook/desktop × consumer/pro. Within this strategy, the iMac was conceived and developed as the “consumer desktop.”

After Jobs’s return, the design team led by Jonathan Ive, who became Apple’s design chief, proposed an all‑in‑one computer with a colorful, translucent enclosure—strikingly novel at the time. In contrast to the sterile, beige, boxy PCs of the day, it adopted a curvy, playful, semi‑transparent body. It also embraced a “legacy‑free” approach focused on internet use, discarding outdated technologies. The product name, proposed by advertising executive Ken Segall, combined the “i” from “internet” with Mac to form “iMac” (it’s said that Jobs initially disliked the name but ultimately adopted it).

The first iMac was announced in May 1998 and released on August 15 the same year. At announcement, some questioned the removal of the legacy floppy disk drive and the unconventional appearance, but the iMac quickly became a smash hit. The strategy of emphasizing how easily home users could connect to the internet paid off: it became the fastest‑selling computer in Apple’s history and went on to sell over six million units in its lifetime. For a struggling Apple, the iMac was truly a “savior,” leading the company back to profitability.

Series Expansion and Model‑by‑Model History

iMac G3 (1998–2003) – Colorful CRT All‑in‑One

The inaugural iMac G3 (a.k.a. Bondi Blue) was an all‑in‑one machine introduced in 1998 with a PowerPC G3 (233 MHz) processor. It featured a translucent, colorful body with an integrated CRT display and was revolutionary in boldly eliminating floppy disks and older expansion ports found on previous models. Key features at launch:

Enclosure – A teardrop‑shaped polycarbonate body housing a 15‑inch CRT monitor. Initially only Bondi Blue was available, but in 1999 five “fruit colors”—Blueberry, Strawberry, Tangerine, Grape, and Lime—were added. Subsequently, new colors such as Graphite (dark gray) and Snow (white) appeared, and even patterned models (the Flower Power and Blue Dalmatian editions in early 2001). In total, the iMac G3 lineup spanned 13 colors.

Display – A 15‑inch CRT supporting 800×600 to 1024×768 resolution. With the translucent shell revealing internal circuitry and structures, it helped ignite a trend for “see‑through” gadgets.

Interfaces – Two USB (1.1) ports were standard—unprecedented in a mass‑market desktop—while ADB, serial, and SCSI were dropped. There was no floppy drive; instead, an optical CD‑ROM drive was built in. Connectivity included a 56 kbps modem and 10/100BASE‑T Ethernet, enabling ready‑to‑use internet access via dial‑up or broadband. The bundled keyboard and mouse matched the body color and connected via USB (the round “hockey puck” mouse was polarizing).

Other – Built‑in stereo speakers; infrared transceiver (early models only); and a mezzanine slot for expansion (early models only). It shipped with Mac OS 8.1, later supporting Mac OS 9 and Mac OS X 10.0 (Cheetah). The iMac’s debut spurred the peripheral industry to accelerate USB accessory development and helped drive the broader shift away from legacy ports.

After launch, the iMac G3 received minor internal updates every few months. In January 1999, CPU speed increased to 266 MHz and HDD capacity grew, along with the introduction of the five fruit colors. In October 1999, the CD drive switched from tray‑loading to slot‑loading, and the iMac DV series was added with enhanced graphics. This model introduced FireWire 400 (a.k.a. i.Link/IEEE 1394) for home users, emphasizing camcorder connectivity. CPU speeds climbed to 333, 400, and 500 MHz, with summer 2000 bringing new Indigo and Ruby colors, and early 2001 adding whimsical patterns. The summer 2001 lineup (500/600 MHz) marked the end of the iMac G3, handing off to the iMac G4 in 2002. Manufacturing continued until March 2003 for inventory balancing.

iMac G4 (2002–2004) – LCD on an Articulating Arm

Introduced in 2002, the iMac G4 represented a major design overhaul. Jobs declared “the CRT era is over,” unveiling a “new iMac (Flat Panel)” that replaced the CRT with a thin LCD. With a distinctive half‑sphere base and an articulated arm supporting the display, it was nicknamed a “desk lamp” in some markets.

Enclosure – A glossy white, approximately 27‑cm‑diameter hemispherical base housed the main components, and a metal arm held the display. The display could be positioned smoothly up/down, left/right, and forward/back, allowing placement exactly where the user wanted—novel at the time. The finish shifted from the previous colorful look to a simple, glossy white monotone.

Display – Debuted with a 15‑inch TFT LCD (1024×768), then added a 17‑inch (1440×900) later in 2002 and a 20‑inch (1680×1050) top model in late 2003. The LCD dramatically reduced depth and improved the modern, space‑saving aesthetic.

Hardware – Powered by PowerPC G4 (700 MHz–1.25 GHz). Memory was PC133 SDRAM (256 MB initially, up to ~1 GB). GPUs varied by revision (e.g., NVIDIA GeForce2/4 MX, GeForceFX series, ATI Rage 128 Ultra/GeForce4 MX). An optical drive was discreetly integrated in the base with a front door; upper models featured a SuperDrive (CD/DVD read/write). HDDs ranged 40–80 GB, and later models optionally offered Bluetooth.

Interfaces – Three USB ports (1.1 → 2.0 in later models) and two FireWire 400 ports improved peripheral connectivity. With FireWire standard, digital video editing was a key use case. There was mini‑VGA for analog video out, 10/100 Ethernet, 56 kbps modem, audio I/O, a built‑in mic, and a special minijack for Apple Pro Speakers. (Bundled peripherals shifted to the white Apple Pro Keyboard and single‑button optical Pro Mouse, via USB.)

Other – Early units supported dual‑boot with Mac OS 9 and Mac OS X, but by late 2002 iMac G4s shipped Mac OS X‑only, a milestone sometimes dubbed the “funeral for OS 9.” 2003 models upgraded from USB 1.1 to USB 2.0. The iMac G4 rekindled innovation in the all‑in‑one Mac lineage dating to 1984, and remains regarded as one of Apple’s iconic designs.

The iMac G4 sold for about two and a half years, receiving minor updates in early and mid‑2003 (faster CPUs, larger HDDs), plus a broadened lineup (17‑inch, USB 2.0, and the 20‑inch model). But as LCDs grew larger across the PC market and demand rose for more powerful CPUs, Apple again overhauled the design in 2004 with the successor iMac G5.

iMac G5 (2004–2005) – Flat‑Panel All‑in‑One (PowerPC)

Announced in August 2004, the iMac G5 marked another design pivot. Abandoning the half‑sphere‑and‑arm, it returned to an all‑in‑one where all computer components sat behind the display, like a thin television. This “display‑integrated” direction has defined iMac design ever since.

Enclosure – A few‑centimeters‑thick rear display chassis housed the logic board, HDD, and optical drive. The front (bezel and wide lower “chin”) was white plastic, the rear a milky plastic with numerous circular vents near the bottom center. Components were concentrated in the lower “chin”, with an aluminum stand supporting from below. Minimal and clean—often called “picture frame”—it set the template for future iMacs. Two sizes: 17‑inch and 20‑inch.

Display – 17‑inch (1440×900) or 20‑inch (1680×1050) wide LCDs with a matte surface and good color. The 17‑inch increased size over the previous 15‑inch; the 20‑inch was the iMac’s first in the 20‑inch class. (The last revision added a small window at the top bezel for the built‑in webcam.)

Hardware – Adopted then‑top‑tier PowerPC G5 (1.6–2.1 GHz) single‑core CPUs, also used in the Power Mac G5 towers—big news for a consumer iMac. Memory: DDR SDRAM (256 MB initially, up to 2 GB). GPUs included NVIDIA GeForce FX 5200 Ultra/GeForce 6600 and ATI Radeon 9600, depending on model. All models had SuperDrive (DVD±R/RW) standard. HDDs ranged 80–250 GB. AirPort (Wi‑Fi) was optional initially, later standard. 2005 models added an ambient light sensor for automatic brightness.

Interfaces – USB 2.0×3, FireWire 400×2, Gigabit Ethernet, 56 kbps modem, and audio I/O. Video output switched from mini‑VGA to mini‑DVI for mirroring/projectors. Legacy infrared ports present in early iMacs disappeared with internal design changes.

Other – The final revision in October 2005 integrated an iSight camera and an IR receiver for Apple Remote media control. Internal modems were removed (USB modem optional). Early G5 iMacs allowed easy service: a few screws removed the rear cover for RAM/HDD access; the iSight models became more complex to open, reducing serviceability.

Across 2004–2005, the iMac G5 shipped in three generations (original, early 2005 refresh, late 2005 iSight). In early 2006, Apple initiated a major architecture transition. With IBM’s G5 development stalling, Apple moved from PowerPC to Intel CPUs, with iMac at the vanguard.

iMac (Intel White Model, 2006) – Transition to Intel

In January 2006, at Macworld Expo in San Francisco, Apple announced the transition of the iMac to Intel CPUs. The Intel‑based iMac (officially just “iMac”), released that day, looked nearly identical to the final iMac G5, but inside carried mobile Intel Core Duo (32‑bit dual‑core) processors. It was the first Macintosh with an x86 architecture, and over roughly six months Apple migrated the entire Mac lineup to Intel.

Enclosure – The white, flat‑panel all‑in‑one design continued from the iMac G5. Visual differences were subtle, with changes to venting and port layout. Sizes remained 17‑inch and 20‑inch, with a 24‑inch option added in late 2006.

Hardware – Early models used Intel Core Duo (1.83/2.0 GHz), upgraded to Core 2 Duo (64‑bit) in late 2006. Memory switched to DDR2 (667 MHz) with higher max capacity; GPUs included ATI Radeon X1600. Mac OS X 10.4 “Tiger” (Intel) ran natively, with Rosetta emulation for PowerPC apps.

Interfaces – Familiar layout with USB 2.0×3, FireWire 400×2, Gigabit Ethernet, optional modem, audio I/O, and Mini‑DVI video out. The 24‑inch introduced FireWire 800 to the iMac line. Wireless included AirPort Extreme (802.11g) and Bluetooth 2.0+EDR, with draft 802.11n support in later Core 2 Duo units.

Other – The 24‑inch model offered 1920×1200 resolution and stronger GPUs (NVIDIA GeForce 7300 GT/7600 GT), making it high‑spec for the time. iLife ’06 (adding iWeb) promoted a digital lifestyle. Apple continued bundling the curvy white Apple Keyboard and wired Mighty Mouse.

The Intel iMac earned praise for major performance gains and better thermals despite its unchanged look. Through mid‑to‑late 2006 it moved to Core 2 Duo, and the 24‑inch (1920×1200) model drew attention for expansive workspace. In 2007, iMac’s design would change again.

Aluminum iMac (2007–2011) – Aluminum & Glass Industrial Design

In August 2007, Apple unveiled a redesigned iMac with aluminum and glass replacing white plastic. Available in 20‑inch and 24‑inch, the front was a glass‑covered glossy display with a black bezel, while the back combined silver and black plastics (later, all‑aluminum).

Enclosure – Edge‑to‑edge strengthened glass on the front with a roughly 5‑cm black bezel. The frame and stand were aluminum, matching a new slim keyboard’s premium look. Early models had a black polycarbonate back; from late 2009 onward the back also became aluminum. The slot‑loading optical drive remained on the side.

Display – 20‑inch (1680×1050) or 24‑inch (1920×1200) widescreen LCDs with a glossy finish; the glass boosted contrast. The 20‑inch used a narrower‑viewing‑angle TN panel, while the 24‑inch used IPS, prompting complaints about color/angle differences. In late 2009, sizes changed to 21.5‑inch (1920×1080) and 27‑inch (2560×1440), and all models switched to IPS, unifying color quality and enabling professional‑grade work.

Hardware – Intel Core 2 Duo (from Merom 2.0 GHz to Penryn 3.06 GHz). The 27‑inch (late 2009) introduced iMac’s first quad‑core Core i5/i7 options for high‑end users. GPUs updated across generations (e.g., ATI Radeon HD 2000/4000 and NVIDIA GeForce 7000/9000 series). Memory moved to DDR3, with the 27‑inch supporting 16 GB (later 32 GB). HDD options grew to 2 TB, and by mid‑2010 Apple offered an SSD as a factory option for the first time. All models kept SuperDrive opticals.

Interfaces – USB 2.0×3–4; FireWire 400×1 (2007–2008) and FireWire 800×1; late 2009 dropped FW400 in favor of FW800 only. Video out switched from Mini‑DVI to Mini DisplayPort in late 2009, enabling higher resolutions and daisy‑chaining. SD card slots were added (on the side). Networking: Gigabit Ethernet, AirPort Extreme (802.11n), Bluetooth 2.x. The 2011 models introduced Thunderbolt (Mini DisplayPort compatible) with two ports, enabling 10 Gbps I/O.

Other – A new Apple Keyboard (Aluminum) replaced the previous white model, available wired and Bluetooth. The mouse transitioned from the wired Mighty Mouse to the Magic Mouse (multi‑touch, wireless) in late 2009. Apple highlighted eco‑friendly materials (aluminum and glass) and reduced hazardous substances.

From 2007–2011, the aluminum iMac iterated steadily. 2008 and early 2009 brought internal speed bumps; late 2009 delivered bigger displays and IPS. Mid‑2010 and mid‑2011 refreshed again, with Sandy Bridge CPUs and Thunderbolt in 2011. The refined design and performance broadened the iMac’s appeal from home to business. The next turning point arrived with the ultra‑thin iMac in 2012.

Ultra‑Thin Unibody iMac (2012–2020) – Ultra‑Slim Aluminum & the Retina Era

In October 2012, Apple again transformed the iMac’s design, unveiling a new iMac with an ultra‑thin 5 mm edge. From the front it resembled its predecessor, but from the side the dramatically thinned edge was striking. Space efficiency improved through modular internal design, and the optical drive was eliminated, making the side profile nearly 80% thinner than before.

Enclosure – A machined‑aluminum unibody with a black‑bezel glass front and brushed‑aluminum back panel. The thinnest part was about 5 mm, with a bulge in the center to house the board and fan. Sizes remained 21.5‑inch and 27‑inch; removing the optical drive even in the 27‑inch cut weight significantly. The glass was adhesively bonded to the chassis (replacing the magnetically attached front glass), increasing difficulty of display replacement/internal access but improving reflections and image quality via lamination.

Display – 21.5‑inch (1920×1080) and 27‑inch (2560×1440) IPS LCDs (matte). In October 2014, the 27‑inch iMac gained the first Retina 5K (5120×2880) display. In October 2015, the 21.5‑inch lineup added Retina 4K (4096×2304). With Retina, GPUs grew stronger—AMD Radeon R9/M series and later Radeon Pro 500/VEGA. The 27‑inch 5K drew praise for rendering over 140 million pixels smoothly for creative pros.

Hardware – The 2012 models used Intel 3rd‑gen Core (Ivy Bridge), with DDR3 1600 MHz RAM (max 16/32 GB) and NVIDIA GeForce 600M graphics. Apple debuted Fusion Drive, a hybrid SSD+HDD that cached frequently used data to the SSD for speed. CPUs progressed yearly (Haswell/Broadwell/Skylake/Kaby Lake/Coffee Lake/Comet Lake), culminating in 10 cores (the 2020 Core i9‑10910). Memory scaled to 128 GB (2020 5K), and large SSDs became standard options. Notably, the August 2020 27‑inch Retina 5K made all‑SSD storage standard, retiring Fusion Drive/HDD for better performance and reliability.

Interfaces – Along with the optical drive, FireWire ports were removed; high‑speed connectivity centered on Thunderbolt. Two Thunderbolt (10 Gbps) ports appeared in 2012, upgraded to Thunderbolt 2 (20 Gbps) in 2014, then Thunderbolt 3 (40 Gbps/USB‑C)×2 in 2017. There were four USB 3.0 (5 Gbps) ports, SDXC slot, Gigabit Ethernet, and audio I/O. Wireless advanced through Wi‑Fi (to 802.11ac) and Bluetooth (to 5.0).

Other – In late 2017, Apple introduced the pro‑oriented iMac Pro (see next section), based on this thin chassis. In 2018, Apple promoted Thunderbolt‑connected eGPU solutions. Spanning roughly eight years (2012–2020), this era steadily maximized performance while staying true to the all‑in‑one concept. 2020 also set the stage for the next big transition: Apple announced a move from Intel to its own Apple silicon (M1).

iMac Pro (2017–2021) – High‑End All‑in‑One for Pros

Previewed at WWDC in June 2017 and released in December, the iMac Pro targeted professional users. It resembled the 27‑inch thin iMac, but came in Space Gray and had markedly different internals.

Chassis & Cooling – The 27‑inch aluminum unibody design returned, but with a revamped thermal system: larger blower and dual hot zones for workstation‑class thermals. Matching Space Gray peripherals—Magic Keyboard (with numeric keypad), Magic Mouse, Magic Trackpad—were included.

Display – 27‑inch 5K Retina (5120×2880) with P3 wide color and high brightness, like the standard model. The built‑in camera was upgraded to 1080p.

Hardware – Intel Xeon W (8–18 cores) CPUs; ECC DDR4 memory (32 GB standard, up to 256 GB); AMD Radeon Pro Vega 56/64 (HBM2 16 GB) GPUs. All‑SSD storage (1 TB to 4 TB). The T2 chip added encrypted storage and Secure Boot. Pricing started at $4,999, framing it as the “most powerful all‑in‑one Mac.”

Interfaces – Thunderbolt 3 (USB‑C)×4, USB‑A×4, 10 Gb Ethernet×1, SDXC slot, and 3.5 mm headphone jack. It was the first iMac with 10‑gigabit Ethernet standard. High‑quality stereo speakers, an internal mic array, and a 1080p FaceTime HD camera rounded out I/O.

Other – User upgrades were minimal; configurations were set at purchase. With Apple’s shift to Apple silicon, Apple announced its discontinuation in March 2021. No direct successor followed; later, Mac Studio + Studio Display addressed many pro desktop needs.

The iMac Pro has been seen as a stopgap after the 2013 cylindrical Mac Pro underwhelmed professionals. Apple later acknowledged it had “hit a thermal corner” with Mac Pro and committed to a new design; the iMac Pro helped bridge the gap. Though a one‑generation product, it earned respect as a formidable all‑in‑one, and Space Gray became something of a status color.

Apple Silicon iMac (2021–Present) – Colorful, Ultra‑Thin M1 Model

In June 2020, Apple announced a two‑year transition from Intel to Arm‑based Apple silicon. About ten months later, in April 2021, the first Apple‑silicon iMac arrived: the 24‑inch iMac (M1).

This 2021 model also brought a fresh design. The display grew from 21.5 inches to 24 inches (4.5K Retina), and the body became an ultra‑thin, flat aluminum slab with vibrant colors reminiscent of the original iMac. At just 11.5 mm thick and powered by a modern system on a chip (SoC), it made big strides in quietness and power efficiency.

Enclosure – Despite the 24‑inch panel, thickness is about 11.5 mm—astonishingly thin for an all‑in‑one desktop. The front uses a white, narrow bezel, and the lower chin is a color‑anodized aluminum panel. Seven colors—Blue, Green, Pink, Silver, Yellow, Orange, and Purple—extend to the accessories, including Magic Keyboard (with Touch ID on some models) and Magic Mouse/Trackpad. The new stand adjusts tilt. Because of the thinness, the 3.5 mm headphone jack sits on the side. The power adapter is external and uniquely integrates a Gigabit Ethernet port. The power cable attaches via a magnetic connector with a color‑matched braided sheath.

Display – 23.5‑inch (24‑inch diagonal) 4.5K Retina at 4480×2520 (218 ppi), 500 nits, P3 wide color, and True Tone. A 1080p FaceTime HD camera at the top center significantly improves video quality.

Hardware – The M1 SoC (8‑core CPU / 7–8‑core GPU) outperforms prior Intel iMacs while using far less power. Memory is 8 GB (or 16 GB CTO), storage 256 GB–2 TB SSD. A fan exists but is very quiet. A 16‑core Neural Engine accelerates ML tasks. Audio is handled by a six‑speaker system with spatial audio support.

Interfaces – The base model has two Thunderbolt / USB4 ports; higher models add two USB‑C (USB 3.0). As noted, Gigabit Ethernet resides on the power brick. Wireless supports Wi‑Fi 6 (802.11ax) and Bluetooth 5.0. SD card and USB‑A ports are gone for a minimalist I/O set.

Other – Touch ID debuts on the iMac’s keyboard, working with the Secure Enclave in Apple silicon for login and authentication (bundled with higher configurations). Three studio‑quality microphones improve voice for video calls. Environmental credentials include extensive use of recycled aluminum/plastic and ENERGY STAR compliance.

The M1 iMac drew attention for echoing the colorful spirit of the G3 in a razor‑thin form. It quickly became the standard desktop Mac replacing the 21.5‑inch line. However, there was no 27‑inch‑class option in 2021, which left some high‑end users wanting. Apple kept the 24‑inch iMac (M1) through 2022, then in October 2023 introduced the 24‑inch iMac (M3) after about two and a half years. The M3 delivered further CPU/GPU gains (up to 2× vs. M1) while retaining the 2021 design and color lineup. The Apple‑silicon iMac line is expected to continue strengthening.

User Reception

From the beginning, the iMac has consistently drawn attention and positive reviews. While some media initially questioned the removal of legacy ports and the unconventional approach, it was welcomed as “a revolutionary home PC that’s easy for beginners,” and, as noted, it was a commercial triumph. The iMac is remembered not only as the “savior that rescued Apple” but as a product that transformed the image of the personal computer—from a “drab office machine” to a “colorful, stylish home appliance.” After its arrival, many competitors released translucent electronics, showing its design influence across the industry.

Reviews for each generation have been broadly favorable. Tech columnist Walt Mossberg called the iMac the “gold standard of desktops,” and Forbes praised the original candy‑colored iMac as a “success that changed the industry.” Tech outlet The Verge, in its 2011 27‑inch iMac review, remarked, “We review the iMac every year, and the conclusion is always the same: the iMac is still the best all‑in‑one computer.” The iMac has long been lauded for its completeness and ease of use as an AIO desktop.

That said, some iMac‑specific issues have been noted. Regarding upgradability, Dan Frakes of Macworld observed that an all‑in‑one limits upgrade freedom for mid‑tier users; you can’t easily swap internals or reuse just the monitor, so when performance lags, you often replace the whole unit. The 2007 20‑inch iMac drew a class‑action over a claimed 6‑bit panel despite advertising “millions of colors” (dismissed in 2009). Complaints have included the early round mouse ergonomics and, more recently, the disappearance of a large‑screen model. Overall, however, user satisfaction is high, and iMac owners show strong loyalty within the Apple ecosystem.

Major Models, Release Years, and Highlights

Below is a chronological summary of the principal iMac models, their release windows, and defining features.

1998: First iMac G3 (Bondi Blue) – PowerPC G3 233 MHz; translucent blue CRT all‑in‑one; bold removal of the floppy drive and legacy ports in favor of USB; a hit as a home internet terminal.

1999: iMac G3 Fruit Colors & DV – Five new color variants; CPU at 266/333 MHz; later iMac DV adds slot‑loading optical drive and FireWire for the first time.

2002: iMac G4 (Flat Panel) – New half‑sphere‑with‑arm “desk lamp” design; PowerPC G4 (700 MHz–1.25 GHz); LCD from 15 to 17 inches, later 20; FireWire standard; USB 2.0 in 2003; last to support Mac OS 9.

2004: iMac G5 – Returns to a flat‑panel all‑in‑one with all components behind the screen; PowerPC G5 (1.6–2.1 GHz); 17/20‑inch LCDs; AirPort wireless support; ambient light sensor in 2005; final revision with iSight camera.

2006: Intel iMac (White) – Transition to Intel Core Duo; outwardly similar to G5 but upgraded to Core Duo/Core 2 Duo inside; 17" / 20", plus first 24" option; FireWire 800 debuts on the late‑year 24‑inch; Mac OS X Tiger (Intel).

2007: Aluminum iMac – New aluminum‑and‑glass design; 20" (1680×1050) and 24" (1920×1200) glossy LCDs; Intel Core 2 Duo; new aluminum keyboard; modern silver/black look replaces white plastic.

2009: Larger Aluminum iMac – In October, sizes increase to 21.5" (1920×1080) and 27" (2560×1440); full aluminum enclosure; quad‑core Intel Core i5/i7 options; SD card slot added; Mini DisplayPort; LED‑backlit LCD improves color.

2012: Ultra‑Thin Unibody iMac – New 5 mm‑edge design; 21.5" (1920×1080) and 27" (2560×1440) matte LCDs; optical drive removed; Intel Core i5/i7 (Ivy Bridge); Fusion Drive option; USB 3.0 and Thunderbolt; adhesive‑bonded glass increases service difficulty.

2014: Retina 5K iMac – 27‑inch model with 5120×2880 5K Retina display; AMD Radeon GPUs; Thunderbolt 2×2; stunning fidelity for pros; replaces the previous non‑Retina 27‑inch.

2015: Retina 4K iMac – 21.5‑inch model gets 4096×2304 4K Retina with wider color; 27" 5K also refreshed; thereafter, new iMacs progressively standardize on Retina.

2017: iMac Pro – Space Gray pro model; 27" 5K, Xeon W (up to 18 cores), Radeon Pro Vega GPUs; ECC RAM up to 256 GB; Thunderbolt 3×4 and 10 Gb Ethernet; workstation‑class AIO starting at $4,999.

2020: iMac Retina 5K (2020) – Final Intel iMac; 27" 5K, 10th‑gen Intel Core (up to 10 cores); T2 chip; 1080p camera, better mics, Nano‑texture glass option; storage goes all‑SSD; last Intel Mac in the iMac line.

2021: 24‑inch iMac (M1) – New Apple silicon M1 design; 24" 4.5K Retina, 11.5 mm thin; seven colors; big CPU/GPU gains; Touch ID keyboard; white bezel and color chin make a bold design statement.

2023: 24‑inch iMac (M3) – About two years after M1, now with M3; CPU/GPU up to 2× vs. M1; retains 2021 design and color palette; seven colors and 24‑inch 4.5K continue; a smoother macOS Sonoma experience.

Conclusion

We’ve traced the iMac’s history from its origins to the latest models. Since 1998, the iMac has consistently integrated cutting‑edge technology with bold design, staying at the center of conversation. It helped popularize new technologies like USB and Wi‑Fi, reimagined the PC as a colorful, playful household object, and pursued thinness and high‑resolution displays to elevate user experience—achievements that can hardly be overstated.

A quarter century on, the iMac remains a pillar of Apple’s lineup. In the Apple silicon era, the newest models combine the original’s colorful spirit with forward‑looking engineering. Larger‑screen revivals and continued performance growth may come, but the iMac’s core concept—“a simple, powerful, and beautiful all‑in‑one”—is unchanged. We will continue to watch an iMac that always stays half a step ahead of the times.