register_globals on or off?

Hi, Could someone explain what the following passage in php.ini means: You should do your best to write your scripts so that they do not require ; register_globals to be on; Using form variables as globals can easily lead ; to possible security problems, if the code is not very well thought of. If register_globals is off, does that mean you cannot access form variables by just referring to their name? And, if that is so, how do you pass information from forms to your action script?