Difference between mysql_connect and mysql_pconnect.

while using mysql_pconnect , the function would first try to
find a (persistent) link that's already open with the same
host, username and password. If one is found, an identifier
for it will be returned instead of opening a new connection...
the connection to the SQL server will not be closed when the
execution of the script ends. Instead, the link will remain
open for future use.