Work is done only when a force moves an object over a distance.
The greater the distance an object is moved, the greater the amount of work done. The heavier the object that is moved, the greater the amount of work done.
If you push or pull on an object and it does not move, you have done no work at all.
When opposing forces are balanced, no work is done.
When the forces are unbalanced, movement occurs in the direction of the stronger force.
The force required to make thinks move may be supplied by our muscles, machines, magnets, wind and water.
The greater the mass of an object, the greater is its gravitational force. The force required to make things move may also be supplied by gravity.