Explain Security System

I have a 2008 prerunner double cab and cannot figure out how the alarm system works. Sometimes it honks when the truck is rocked, sometimes it doesnt. Sometimes the alarm goes off, sometimes it doesnt.

Is there a certain way of locking my car that arms it?

if anyone can tell me how it works in laymen's terms, I would be very grateful.

 

Generally works by impact and or the act of opening a door without prior authorization. So gently rocking your truck might not set it off, but slamming into it might.

(Author does not pretend to be an expert in this subject. Readers are advised to go into the kitchen and take a pinch of salt with viewing of the above post)