PHP Interview Questions
What is a PHP Session ?
PHP session supports in consists of a way to preserve certain data across subsequent accesses.

A visitor accessing your web site or web application is assigned a unique id,  session id. This is either stored in a cookie on the user side or is propagated in the URL.

A PHP session is easily started by making a call to the session_start() function. This function first checks if a session is already started and if none is started  then it starts one. It is recommended to put the call to session_start() at the beginning of the page.