Soldering irons differ in size, power and features. But most have the same basic parts, including the base, cord, handle, heating element and tip.
Soldering irons with automatic heat controls have a base that plugs into the wall and controls the current to the iron. Some bases include a holder and a sponge to clean the tip.
Electric soldering irons have a cord that either plugs into the wall or into a base for heat control. The cord on a soldering iron used with a base cannot be plugged into a wall socket.
Handles vary in size and materials, depending mainly on how hot the iron gets. The handle must insulate the operator from heat so that he can work comfortably.
The heating element, usually rated in watts, must heat the tip sufficiently to melt the solder. A higher wattage heating element heats a larger tip.
The soldering iron tip comes in many sizes and shapes, from a pin point for precision soldering to a wider tip for larger wires. The tip must be appropriate for your soldering job.