What are characteristics of friction

Friction is a force that is created by two surfaces that come into contact.  Depending upon the two surfaces that are doing the contacting, a little or a lot of destructive power may be created.  This depends on the roughness or smoothness of the surfaces.  Each surface, microscopically speaking, has lots of tiny grooves or cracks in it.  When the two surfaces contact, the grooves and cracks interlock with each other, making movement between the two surfaces difficult.  Heat is a common product generated by the two surfaces, as they contact each other.  A good example of friction is rubbing your two hands together.  In a short amount of time, enough friction will be created to heat your hands up.  Different amounts of friction may also be demonstrated by using different surfaces, such as pushing a loaded box across carpet (rough) and a tile floor (smooth).