BLOB: Binary Large OBject (BLOB) is a binary data collection stored as a single entity in a database management system.
CLOB: Character Large OBject (CLOB) is a database management system collection of character data, usually stored in a separate location.
You can write a binary large object (BLOB) to a database as either binary or character data depending on the type of field in your data source. To write your database a BLOB value, issue the appropriate INSERT or UPDATE statement and pass the BLOB value as an input parameter. You can pass the BLOB as a string parameter if your BLOB is stored as text, such as a SQL Server text field. If the BLOB is stored in binary format, such as an image field for SQL Server, you can pass a type byte array as a binary parameter.
Blobs are used to store images, audio files, and video clips, often requiring more space than other data types. Depending on the type of database, the amount of data a blob can store varies.
A CLOB is a data type used by various database management systems, including Oracle and DB2. It stores up to 4 GB in size, large amounts of character data. The data type of CLOB is similar to a BLOB. But includes character encoding, which defines a set of characters and the representation of each character. The CLOB data type may be used if the standard character data types are not large enough for a specific database field. Some database does not store the text as an address that refers to the location of the data.
CLOBs provide a way to store extraordinarily large quantities of text, such as a whole book or publication. However, some database programs can not perform certain text operations on CLOB fields, such as SQL commands ‘ “LIKE” condition.