difference between blob and long raw

I am going to create a table to store employee images in a table called emp

emp will contain a lot of column's to store the data of the employees and a column for employee image (in the format of JPG file)

when I create the table, which data type do you prefer for the column of the  employee image

Blob or Long Raw

please also I want to know the diference between them.

which is the recent, which of them compress the image to don't effect of the table size.

thanx in advance