Soldering and desoldering
Soldering is a way of joining wires together by melting metals so they stick together. It's related to welding but occurs at a much lower heat and does not join the metals together.
Soldering is defined as "the joining of metals by a fusion of alloys which have relatively low melting points". In other words, you use a metal that has a low melting point to adhere the surfaces to be soldered together. Soldering is more like gluing with molten metal than anything else. Soldering is also a must have skill for all sorts of electrical and electronics work. It is also a skill that must be taught correctly and developed with practice.
Soldering requires a metal with a low melting point - the solder.