All matter is made of atoms. Atoms are the smallest particle of matter. They are so small that you cannot see them with your eyes or even with a standard microscope. A standard sheet of paper is about a million atoms thick.
Answer Wiki. The int type is a 4-byte signed integer. There are also tinyint (1 byte), smallint (2 bytes), and bigint (8 bytes), and unsigned versions of all of these. As Apostolos mentioned, the docs for all the numeric types are here: http://dev.mysql.com/doc/refman/...
For example, even though most implementations of C and C++ on 32-bit systems define type int to be four octets, this size may change when code is ported to a different system, breaking the code. The exception to this is the char data type, whose size is always 1 in any standards-compliant C implementation.