A force field is basically an invisible shield. You push a button and all of a sudden a bubble forms around you which is impenetrable. It can stop bullets, it can stop ray gun blasts and we realized force fields are actually a little bit difficult to create.
It would be great if we had our own personal force fields. Just imagine creating your own architecture in your room. Buildings. You wouldn't have to spend all that time saving your money for that second house. You'd simply push a button and have as many houses as you want.