The smallest unit of data in a database is a bit or character, which is represented by 0, 1 or NULL. Numbers may also be stored in a binary format.
The bit values are grouped into bytes, which comprise 8 bits. Bytes represent a specific character, special symbol or character code. The string values TRUE and FALSE may also be stored or converted to bit values. In this case, TRUE becomes 1, and FALSE becomes 0.
Depending on the type of server, a database engine may store information in bit columns, which are, in turn, stored as bytes. In some cases, the engine rounds the bits up to the nearest byte. For example, 6 bits are stored as 1 byte, and 12 bits are stored as 2 bytes.