go on http://www.bbc.co.uk/schools/scienceclips/ages/5_6/pushes_pulls.shtml to find out more

smee:whats all the pushing and pulling about
captian hook: pushing and pulling is another type of force

friction is a force when 2 surfaces
meet like when you are climbing up a
mountain the friction on the bottom
of the boot stops you from sliding
down the mountain.

forces