TIG welding is an arc process whereby you create the arc with an electrode and add the filler wire by hand. The electrode used is made of tungsten which is a rare metallic element. Tungsten has the highest melting point of any metal, 3,410 °C
Tungsten electrodes come in a varying degree of sizes depending on the material you want to weld and the welding current you want to use.
Each electrode is colour coded to eliminate any confusion and it appears at the end of the electrode.