What is BLOB and its types in MYSQL? BLOB is LARGE binary OBJECT which can have a variable amount of data. Below are the some of very important aspects of BLOB. (1)BLOB is the FAMILY of column type intended as high-capacity binary storage. (2)Actually BLOB column is of 4 types (i)TINYBLOB (II)BLOB (iii)MEDIUMBLOB (iv)LONGBLOB (3)Four of above BLOB types are similar the only difference is the amount of information data each can store.