Passlock/Security please explain

What exactly is the passlock and security? What do they do?

Sometimes after I get gas, I roll up the windows, start the car, and the security light comes on. Any idea why?

What's the anti-theft light on the stock cd player?

Passlock, is a type of security system in the car. Basically what it's susposed to do is, if someone break into the car and tries to hotwire the car it'll trigger the system and the car won't start, it also can be triggered through the key as well when putting it into the ignition the system will think that a "wrong key is being put in" and that'll trigger the system.

the anti theft on the radio basically is if someone steals your radio they can't put it in there car...without proper codes.... etc

Thanks. What about the security light?

Security light is to let you know if the system has been activated, in the sense that if something were to happen and the car thinks it being tampered with when you try to start the car that light will come on and the car will not start.