the other kind of welding that does not use an arc still uses electricity. it is called resistance welding. with this kind, two pieces of thin metal are pinched together and then electricity is made to go through them. this makes the metal get really hot and melt where it is pinched together. the two pieces melt together at that place. sometimes this is called spot welding because the welding can only happen at one small place(or spot) at a time.