Why is TIG welding a constant current welding operation and MIG welding is a constant voltage welding operation?

At the point when you're MIG wire or GMAW welding, the welding machine works in an unexpected way. Your current is controlled by the speed of the wire leaving the light head every moment. In the event that I am welding in a straight line and my light draws nearer and further away from the work, my amperage is hypothetically changing, while my voltage continues as before. I set my voltage to adjust the circular segment or electrical weight, this encourages me to change how the metal is stored on the workpiece. I can control the voltage to accomplish the strategy for metal exchange which stays steady while I weld.