Friction is the resistances to movement, typically this is as two surfaces slide or roll over each other; one could be stationary or both could be in motion. In an engineering/tribological context, the level of friction typically represents the energy lost, typically as heat and thus is minimised. This could involve design, material selection, and the application of coatings or surface treatments or the use of lubricating fluids or solids.
In some situations, high-levels of friction are require, such as the footwear to floor surface or hand to racket grip in sports. This also includes anything that is gripped or fastened so that it should not move.
nCATS has a range of equipment for the evaluation of friction in sliding and rolling contacts, these include fundamental measurements at the nano-scale.