Tracing between 2 vectors

I’ve been reading up on dot products and it still isn’t making a whole lot of sense to me. If I have ent1:GetPos() and ent2:GetPos(), how would i find the angle from ent1 to ent2?

[lua](ent2:GetPos() - ent1:GetPos()):Angle()[/lua]

[editline]08:00PM[/editline]

That will return a 3 dimensional angle (pitch, yaw, roll).

Thanks