The concept behind soldering has been around much longer than most people realize. The process is said to first date back to Mesopotamia. The word "solder" itself comes from the Latin word "solidare", meaning "to make solid". That's exactly what solder guns do: make things solid through a process called soldering. Commonly seen in the plumbing and electronic fields, soldering is a process in which two (or more) metals are bonded together by using a solder gun to melt and then fill in a joint with a filling metal. Solder guns are important tools to have when metals need to be joined and welding them is simply not an option.