why is $_POST Function used in php?

why is $_POST Function used in php?????

Hi Balu,
The built-in $_POST function is used to collect values in a form with method="post".Information sent from a form with the POST method is invisible to others and has no limits on the amount of information to send.
Note: However, there is an 8 Mb max size for the POST method, by default (can be changed by setting the post_max_size in the php.ini file).