It is a program able to store huge amounts of disparate data and then returns them back on a request. Data is stored in tables. Professionally MySQL is a relational database management system (RDBMS). MySQL uses the language SQL (Structured Query Language).
MySQL was created by Michael Widenius and David Axmark in 1994 and a year later was published in the first version. Product MySQL was owned by MySQL AB, then Sun Microsystems and currently by Oracle Corporation.
MySQL is flexible. It supports more than 20 platforms including Linux, Windows, Mac OS, Solaris, IBM AIX.
MySQL in practice: MySQL is used mainly by web programmers. No web presentation or application can nowadays work without a database. MySQL is used by many global companies and they run their large-scale projects on it. These include Facebook, Google, Adobe, Alcatel Lucent and Zappos. MySQL competitors are for example Oracle, SQL Server and DB2.