collider without rigidbody

hi, what are the difference between colliders with rigidbody and colliders without rigidbody? will there be a difference in the collision behavior?

See the unity pages: http://unity3d.com/support/documentation/Components/class-BoxCollider.html for details.

I like to say that a rigidbody makes it a “physics object” – it has a speed and can be knocked around. The physics engine moves ridigbodies, and checks against colliders. A collider with no rigidbody is OK for walls, solid trees, very heavy dressers…

If you have a bullet, it needs a rigidbody, or it will just sit where you fired it. Of course, you can write a script to do whatever you want: moving platforms are plain colliders moved via script (so anything that hits them will treat them as immobile walls, bouncing right off w/o shaking the platform.)

The actual results of a collision – hitting a non-rigidbody will give more bounce, since you can’t knock it backwards. But, you can set the bounce in physics materials anyway.