What is spot welding and where is it commonly used?

Spot welding (Resistance Spot Welding) joins metal sheets by applying pressure and passing high current through the contact point, generating heat through electrical resistance to fuse the materials. It is extensively used in automotive body assembly (a typical car has 3000-5000 spot welds), appliance manufacturing, and sheet metal fabrication due to its speed, automation capability, and suitability for thin gauge materials.