Final answer:
When workpieces are heated below their melting point to join them, the process is known as brazing. Welding involves melting the workpieces themselves, whereas soldering uses lower temperatures than brazing.
Step-by-step explanation:
In the processes of welding, brazing, and soldering, different levels of heat are applied to join metal workpieces. When workpieces are heated below their melting point and a filler metal is used to join them, this process is known as brazing. Unlike welding, where the base metals are also melted, in brazing, only the filler metal is melted. Soldering is similar to brazing but typically occurs at even lower temperatures and with different filler materials, often used in electronics. Welding involves the melting of the workpieces themselves, often with the addition of a filler material to facilitate the bond.