What is a basic type of welding operation?

Resistance welding is considered a fundamental type of welding operation as it involves joining two pieces of metal by applying pressure while passing an electric current through the materials. This causes them to heat up at the contact points due to electrical resistance, allowing them to fuse together effectively. Resistance welding is widely used in various industries due to its efficiency and the minimal amount of heat generated, which reduces distortion and promotes good quality welds.

The other options provided are related but do not represent basic types of welding in the same straightforward way. Arc flash pertains to electrical hazards that can occur during various operations, including welding, but it is not a type of welding itself. Oxygen-argon gas is a reference to gas shielding used in certain welding processes, like TIG (Tungsten Inert Gas) welding, but it does not stand alone as a type of welding operation. Understanding the distinctions between these processes helps clarify the fundamental approaches to welding and the importance of each in different applications.