* Static Friction: When an object is at rest, there can be a force of static friction acting on it, even if the object doesn't move. This force opposes any applied force that tries to initiate movement. Think about pushing a heavy box – you might push with some force before it actually starts moving. This is static friction working against you.

* Friction and Work: Friction does work when there is relative motion between surfaces. If an object is stationary and the applied force is not enough to overcome static friction, there is no relative motion, and therefore no work done by friction.

In Summary:

* If an object doesn't move, it doesn't necessarily mean there's no friction. There could be static friction acting on it.

* Friction only does work (transfers energy) when there is relative motion between surfaces.

Let me know if you have any other questions!