An object experiances a force if it's pushed or pulled, and is measured in newtons. These forces are represented as arrows in force diagrams, these arrows give information on how big and in what direction the forces act.
When all the forces experianced by an object are equal to zero they are said the be balanced and due to Newton's first law the object will either stay still or stay moving at a constant velocity.
Balancing forces can be represented in an equation. We say the overall force is the net force (Fnet) and each force is represent by F1, F2, ... Fn. So if the all of the forces are balanced then:
Fnet = F1 + F2 = 0