Gmail is a free POP3 and IMAP webmail service provided by Google. In the United Kingdom and Germany it is officially called Google Mail.
Gmail launched on 1 April 2004 as an invitation-only beta release and became available to the public on 7 February 2007. To this day the service remains in beta status and has tens of millions of users.
With an initial storage capacity of 1 GB, Gmail drastically increased the standard for free storage from the 2-4MB its competitors offered at that time. The service currently offers over 7200 MB of continuously increasing (at a rate of 353.9 KB a day) free storage with additional storage ranging from 10 GB to 400 GB available for $20 to $500 (US) per year.
Gmail has a search-oriented interface and a “conversation view” similar to an Internet forum. Software developers know Gmail for its use of the Ajax programming technique.
(Source: Wikipedia)