a simple real life example.

 

--> WALKING.

 

when u walk u push d ground with ur leg at sum angle. then arises an equal contact force.in d opposite direction. as u know vectors can b resolved into two directions. therefore u hv two componeents 1 parallel & 1 perpendicular. d perpendicular component is d normal force, d parallel(i mean parallel to d ground) component is d frictional force.tht frictional force helps u to move forward. if u hv any queries jus reply.