Solder is a metal alloy used to join two or more electronic components together. It typically consists of a mixture of tin and lead, although lead-free alternatives are also available. When heated, solder melts and flows into the joint, creating a strong electrical and mechanical connection once it cools and solidifies. In electronics, soldering is a crucial process for assembling circuit boards and connecting wires. The tool used for this process is called a soldering iron, which heats the solder to its melting point. Proper soldering techniques ensure reliable connections, which are essential for the functionality of electronic devices.