why do we use div tag??

Answer 1

divs are used as containers for other elements.
For example if you want to divide your website into two columns, you could use two divs, which would contains all the elements of the column.

Answer 2

div is used for divide html pages.. with the help of css or make boxes .

Answer 3

because we're writing in HTML 😁

Answer 4

for this http://www.tutorialspoint.com/html/html_div_tag.htm