what is difference between longtext and mediumtext

[sumaira]

i am basically making a module for taking backup of database when any user come on index page i have created a table of data different datatypes through mysql_field_len() method i get length of longtext and medium text but the length returning is same

[Weedpacket]

From looking at the stuff written in the obvious place and one or two of the links on that page, LONGTEXT fields can hold more than MEDIUMTEXT fields (how much that is depends); this is not necessarily the same as how big they actually are, of course, because otherwise MySQL would use 4GB to store the letter 'a'.