What is the difference?

Name N AWS Characteristics Applications
Bare metal arc welding (113) BMAW Consumable electrode, no flux or shielding gas Historical
Carbon arc welding (181) CAW Carbon electrode, historical Copper, repair (limited)
Flux cored arc welding 136
137 FCAW
FCAW-S Continuous consumable electrode filled with flux Industry, construction
Gas metal arc welding [3] 131
135 GMAW Continuous consumable electrode and shielding gas Industry
Gas tungsten arc welding [4] 141 GTAW Nonconsumable electrode, slow, high quality welds Aerospace,Construction(piping),Tool and Die
Plasma arc welding 15 PAW Nonconsumable electrode, constricted arc Tubing, instrumentation
Shielded metal arc welding [5] 111 SMAW Consumable electrode covered in flux, can weld any metal as long as they have the right electrode Construction, outdoors, maintenance
Submerged arc welding 121 SAW Automatic, arc submerged in granular flux
Magnetically Impelled Arc Butt 185 MIAB both tube ends are electrodes; no protection gas; arc rotates fast along edge by applied magnetic field pipelines and tubes
Atomic hydrogen welding (149) AHW Two metal electrodes in hydrogen atmosphere