blob in SQL

The four BLOB types are TINYBLOB, BLOB, MEDIUMBLOB, and LONGBLOB. These differ only in the maximum length of the values they can hold. 
data type | maximum length
----- | ------
TINYBLOB | 2^8-1, 255
BLOB | 2^16-1, 64K 
MEDIUMBLOB| 2^24-1, 16M
LONGBLOB | 23^2-1, 4G