Welding is a fusion methodology that joins material, usually metals or thermoplastics. This is often done by melting the work pieces and adding a filler of the similar material to form a pool of liquified material. The soften pudle therefore created, once cools down, forms a robust joint (as if the two metal pieces were just one piece).
Welding may be done by applying pressure along with heat or by heat itself. Pressure or energy sources may be in the form of a gas, an electrical arc, a laser, an electron beam, friction, and ultrasound.
Whereas, soldering and brazing are gas welding processes whereby alone gas flame is employed to melt just the low-melting point filler material to fill the gap. In this process, the base material does not melt.
Hence, the top result is that welding creates a far stronger joint in distinction to Soldering / Brazing.
Today welding is done in numerous industries ranging from aircraft and rocket engines to small pipes.