"The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd. Referred to during development as the ZX81 Colour and ZX82, the machine was launched as the ZX Spectrum by Sinclair to highlight the machine's colour display, compared with the black-and-white of its predecessor, the Sinclair ZX81. The Spectrum was released in eight different models, ranging from the entry level model with 16 KB RAM released in 1982 to the ZX Spectrum +3 with 128 KB RAM and built in floppy disk drive in 1987.
The Spectrum was among the first mainstream audience home computers in the UK, similar in significance to the Commodore 64 in the USA. The introduction of the ZX Spectrum led to a boom in companies producing software and hardware for the machine, the effects of which are still seen; some credit it as the machine which launched the UK IT industry. Licensing deals and clones followed, and earned Clive Sinclair a knighthood for "services to British industry".
The Commodore 64 was a major rival to the Spectrum in the UK market during the early 1980s. The BBC Microcomputer and later the Amstrad CPC range were other major competitors. The ZX Spectrum has incurred a resurgence in popularity thanks to the accessibility of ZX Spectrum emulators, allowing 1980s video game enthusiasts to enjoy classic titles without the long loading times associated with data cassettes. Over 20,000 titles have been released since the Spectrum's launch, with over 60 new ones in 2009.
Source: Wikipedia, "Sinclair_ZX_Spectrum", available under the CC-BY-SA License.