The welding processes, in their official groupings. The letter designation assigned to the process can be used for identification on drawings, tables, etc. Allied and related processes include adhesive bonding, thermal spraying, and thermal cutting. Capillary attraction distinguishes the welding processes grouped under "Brazing" and "Soldering" from "Arc Welding", "Gas Welding", "Resistance Welding", "Solid State Welding", and "Other Processes."

The American Welding Society has made each welding process definition as complete as possible so that it will suffice without reference to another definition. They define a process as "a distinctive progressive action or series of actions involved in the course of producing a basic type of result".

The official listing of processes and their grouping is the AWS Master Chart of Welding and Allied Processes. The welding society formulated process definitions from the operational instead of the metallurgical point of view. Thus the definitions prescribe the significant elements of operation instead of the significant metallurgical characteristics.