Question

how does frictional force work

Answer 1

Frictional force always works opposite to the motion and along the surface in contact of the object..

Answer 2

friction: is the resistance that one surface or object encounters when moving over one another.
so frictional force thereby helps us to :
.walk on ground as it opposes relative motion
.tighten our soles of the shoes
.helps vehicles to move somewhat stiffly .
.helps to produce heat energy.
so in the above cases it can be seen that frictional force helps us by making the surface of an object tough..