The Apple II series (trademarked with square brackets as "Apple ][" and rendered on later models as "Apple //") is a family of home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer (now Apple Inc.), and launched in 1977 with the original Apple II.
In terms of ease of use, features, and expandability, the Apple II was a major advancement over its predecessor, the Apple I, a limited-production bare circuit board computer for electronics hobbyists. Through 1988, a number of models were introduced, with the most popular, the Apple IIe, remaining relatively unchanged into the 1990s.
A 16-bit model with much more advanced graphics and sound, the Apple IIGS, was added in 1986. While compatible with earlier Apple II systems, the IIGS had significantly different hardware, more in league with the Atari ST and Amiga.

The Apple II was first sold on June 10, 1977. By the end of production in 1993, somewhere between five and six million Apple II series computers (including about 1.25 million Apple IIGS models) had been produced. The Apple II was one of the longest running mass-produced home computer series, with models in production for just under 17 years.
The Apple II became one of several recognizable and successful computers during the 1980s and early 1990s, although this was mainly limited to the US. It was aggressively marketed through volume discounts and manufacturing arrangements to educational institutions, which made it the first computer in widespread use in American secondary schools, displacing the early leader Commodore PET. The effort to develop educational and business software for the Apple II, including the 1979 release of the popular VisiCalc spreadsheet, made the computer especially popular with business users and families.

Despite the introduction of the Motorola 68000-based Macintosh in 1984, the Apple II series still reportedly accounted for 85% of the company's hardware sales in the first quarter of fiscal 1985. Apple continued to sell Apple II systems alongside the Macintosh until terminating the IIGS in December 1992 and the IIe in November 1993. The last II-series Apple in production, the IIe card for Macintoshes, was discontinued on October 15, 1993. The total Apple II sales of all of its models during its 16-year production run were about 6 million units, with the peak occurring in 1983 when 1 million were sold.