Question

what is force of friction?How can it be minimised?

Answer 1

Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving surfaces.

Answer 2

when 2 objects pass over each other a force that is produced is called frictional force.they are of many types:
rolling
sliding
fluid

it can be minimised by greasing, using ball bearing, and colouring mechanical parts