The idea for a personal computer appropriate for the ordinary consumer dates to the late 1970s and an Apple development team was established in 1979. After the success of the original Macintosh in 1984, the company quickly established market share only to see it dissipate in the 1990s as Microsoft came to monopolize personal computing. Apple consolidated multiple, consumer-level desktop models into the 1998 iMac all-in-one, which sold extremely well and saw the brand name revitalized. Current Mac systems are mainly targeted at the home, education, and creative professional markets. They are: the aforementioned (though upgraded) iMac and the entry-level Mac mini desktop models, the workstation-level Mac Pro tower, the MacBook, MacBook Air and MacBook Pro laptops, and the Xserve server.

Production of the Mac is based on a vertical integration model in that Apple facilitates all aspects of its hardware and creates its own operating system that is pre-installed on all Macs. Apple exclusively produces Mac hardware, choosing internal systems, designs, and prices. Apple does use third party components, however; current Macintosh CPUs use Intel's x86 architecture. Previous models used the AIM alliance's PowerPC and early models used Motorola's 68k. Apple also develops the operating system for Macs, currently Mac OS X 10.5 "Leopard". This is in contrast to most IBM compatible PCs, where multiple vendors create hardware intended to run another company's software. The modern Mac, like other personal computers, is capable of running alternative operating systems such as Linux, FreeBSD, and Microsoft Windows, the latter of which is considered to be the Mac's biggest competitor.

Since the introduction of the Macintosh, Apple has struggled to gain a significant share of the personal computer market. At first, the Macintosh 128K suffered from a dearth of available software compared to IBM's PC, resulting in disappointing sales in 1984 and 1985. It took 74 days for 50,000 units to sell.[57] By 1997, there were more than 20 million Mac users, compared to an installed base of around 340 million Windows PCs.[58][59] Statistics from late 2003 indicate that Apple had 2.06 percent of the desktop share in the United States, which had increased to 2.88 percent by Q4 2004.[60] As of October 2006, research firms IDC and Gartner reported that Apple's market share in the U.S. had increased to about 6 percent.[61] Figures from December 2006, showing a market share around 6 percent (IDC) and 6.1 percent (Gartner) are based on a more than 30 percent increase in unit sale from 2005 to 2006. The installed base of Mac computers is hard to determine, with numbers ranging from a conservative 3 percent[62] to an optimistic 16 percent.[63] Three ways of measuring marketshare are: i) by browser hits, ii) by sales, and iii) by installed base. If using the browser metric, Mac Marketshare has increased substantially in 2007[1]. However, results for market share measured as a percentage of current sales provides different results than when market share is measured by installed base. Apple computers often have a longer life than PCs of the same vintage, since Apple provides their own system software, and newer versions often optimize older hardware (e.g. OS 8.1 provided faster copy speeds and PowerPC optimizations that weren't yet implemented in OS 7.6).

Whether the size of the Mac’s market share and installed base is actually relevant, and to whom, is a hotly debated issue. Industry pundits have often called attention to the Mac’s relatively small market share to predict Apple's impending doom, particularly in the early and mid 1990s when the company’s future seemed bleakest. Others argue that market share is the wrong way to judge the Mac’s success. Apple has positioned the Mac as a higher-end personal computer, and so it may be misleading to compare it to a low-budget PC.[64] Because the overall market for personal computers has grown rapidly, the Mac’s increasing sales numbers are effectively swallowed by the industry’s numbers as a whole. Apple’s small market share, then, gives the false impression that fewer people are using Macs than did (for example) ten years ago.[65] Others try to de-emphasize market share, citing that it's rarely brought up in other industries.[66] Regardless of the Mac’s market share, Apple has remained profitable since Steve Jobs’ return and the company’s subsequent reorganization.[67] Market research indicates that Apple draws its customer base from a higher-income demographic than the mainstream PC market. Higher income theoretically correlates with greater artistic, creative, and well-educated social behaviors, which may explain the platform’s visibility within certain youthful, avant-garde subcultures.[68] Steve Jobs speculates that “maybe a little less” than half of Apple’s customers are Republicans, “maybe more Dell than ours.”[69] This perception may or may not be accurate—several prominent conservatives, including Rush Limbaugh, are Mac users[70]—but it can only be reinforced by the company's pattern of political donations,[71] by Al Gore’s membership on its board,[72] and surely not least by Jobs’ own personal history.