Final answer:
TIG welding is the process that uses a non-consumable electrode, as opposed to friction welding and other types, which do not use such an electrode or consume the electrode during the welding process.
Step-by-step explanation:
The process that uses a non-consumable electrode is TIG (Tungsten Inert Gas) welding. During TIG welding, a non-consumable tungsten electrode is used to create the arc for welding without itself being consumed in the process. It is different from other welding methods like Metal Inert Gas (MIG) welding, spot welding, and friction welding, where either the electrode is consumed or no electrode is used. Friction welding utilizes mechanical motion and material deformation to generate heat and join materials, instead of using a non-consumable electrode.