What is the difference between filler and electrode in Welding? Can a filler be an electrode? Can an electrode be a filler? Why?

Filler:

Filler is the material rod is used when we are joining two material by using welding process. If thickness of work piece is more so it will become compulsory to provide some filler material for making the welding join to withstand high stresses.

Electrode:

Electrode is the element which is used to complete the electric circuit in welding. Some time electrode is connected with positive terminal and some time with negative terminal, it depends on the requirement of welding process. In Tungsten inert gas welding electrode is connected negative terminal but on the other hand Metal inert gas welding electrode is connected with positive terminal. Electrode can be consumable non-consumable depends on the condition.

Yes electrode can be work as filler material, in Metal inert gas welding wire is used as electrode as well as filler material. In Metal inert gas welding consumable electrode is used on the other hand Tungsten inert gas welding non-consumable electrode is used. In Tungsten inert gas welding if thickness of work pieces is less than 5 mm then no need to used any filler material but if thickness is more than 5 mm then we have to use filler material.