Soldering iron is quite popular hand tool commonly used to solder components with each other. It works on a very basic principle. When we pass current through a high resistant material, heat is generated. We use this heat to melt down a conductor metal also called soldering wire and putting it between two components in order to connect them electrically.A general soldering iron consists of a heating region and an insulated handle. On supplying electrical current to the soldering iron, the heating tip gets heated and with the help of a soldering wire it joins two components. 

Soldering – a must skill for all electrical and electronic works. ‘Soldering’ is defined as the process of joining two pieces of metals using a filler metal, known as solder, having a low melting point below the melting point of the work piece. It is often confused with welding but the difference in between them is, in soldering the work piece is not melted, they are joined using a filler metal, but in welding work piece is joined by melting.  Soldering was practiced as far back as 5000 years ago in Egypt. Soldering was widely performed around 4000 years ago when tin was discovered as soldering metal. Soldering process was introduced in Mediterranean region, and was followed in the Roman Empire, Swiss and Hungaria.