What is output buffering?

Question

What is output buffering and why is one using it in PHP?

Answer 1

The Output Control functions allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputting data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo() and data between blocks of PHP code.

http://php.net/manual/en/book.outcontrol.php

More Resources:

Output Buffering With PHP