Soldering is a process in which two or more metal pieces are joined together by melting and flowing a filler metal into the joint. It is a type of welding that uses an alloy, such as lead and tin, to create a strong bond between the two metals. The alloy is melted at a high temperature and then applied to the joint, where it cools and solidifies, creating a strong bond. Soldering is often used in electronics and plumbing, as well as in jewelry making.