Blob Data Type

BLOB refers to large binary-valued image data. CLOB refers to large text data, and NCLOB refers to large ntext data.
Blob data is a field that holds large amounts of data per record. This data can be either in a text format or a binary format.
When working with blob data in SQL Server, the amount of data per record is typically well beyond the 8K of data that can fit within a single record.

We can insert large amount data like image (in the binary format), text file etc.