Final answer:
In the context of welding, plasma is an electrically-conductive ionized gas used in plasma cutters for metal cutting. It is the fourth state of matter, with unique properties distinct from solids, liquids, and gases.
Step-by-step explanation:
From a welding perspective, plasma can best be described as an electrically-conductive ionized gas. This state of matter is what allows plasma cutters to slice through metal by creating a focused plasma stream, as they generate an electrical channel of superheated, electrically ionized gas. Plasma cutting is a process that involves the use of a plasma torch to cut through various types of metal. It is important to note that plasma is often referred to as the fourth state of matter, distinct from solids, liquids, and gases because of its unique properties such as being made up of a mixture of free-flowing ions and electrons.