Dan Bowen & Diana Butler 
BCS Glossary of Computing [PDF ebook] 

The BCS Glossary is the most authoritative and comprehensive work of its kind. This unrivalled study aid and reference tool has newly updated entries and is divided into themed sections making it more than just a list of definitions. Written in an easily accessible style, it is specifically designed to support those taking computer courses or courses where computers are used, including GCSE, A-Level and 14-19 Functional Skills qualifications in schools and further education colleges.