Weight affects friction in that friction is directly proportional to the weight of the load one is moving. If one doubles the load being moved, friction increases by a factor of two.
Friction is the force that opposes motion of one object over another. Friction is sometimes beneficial as when preventing slipping of the feet when walking. However, when attempting to move an object, friction requires additional force to complete the job. Since rolling friction is less than sliding friction, wheels or ball bearings help to reduce the force required to move an object. Lubricants help to reduce both rolling and sliding friction. Reducing friction also reduces the heat caused in the moving process.