Mechanisms change an input force into an output force, changing direction or magnitude.
There are different types of movement.
Linear movement is in a straight line in one direction.
Reciprocating movement is in a straight line in two directions.
Rotary movement is movement on or around an axis.
Oscillating movement is movement back and forth along a curved path.
Some simple mechanisms are
Inclined plane
Screw
Wheel and axle
Wedge
Lever
Pulley
Mechanical advantage is a measure of the force amplification achieved by using a mechanism.
It is calculated by dividing load by effort.