can you please help me.

i want to make my webserver more secured, and i want to be able to change my settings to time out instead of just staying forverver. i think by default, apache times out after a certain period. but im not sure if this is really set in apache or in php. i searched /etc/httpd/conf/httpd.conf and /etc/php.ini but i could not find any settings with sessions.. the closest i could find was this:

#
# Timeout: The number of seconds before receives and sends time out.
#
Timeout 120

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
#
KeepAlive Off


thanks in advance