Soldering Iron
This tool heats up as soon as it is plugged in and can reach extremely high temperatures very quickly. Extreme caution should be taken from the moment it is plugged in until at least 15 minutes after it is switched off. Due to the heat this tool generates, it can easily pose a fire risk as well as an extreme burn risk. Make sure to use on a solid, flat surface with no flammable materials or liquids nearby. If the tool falls from its stand during use, it can quickly ignite solid wood and other household materials. If the iron touches its own power cable when hot, it will quickly melt through it, leading to serious risk of fire and possible electrocution.
Soldering irons use high temperatures to melt conductive soft metals in order to join electrical components like wires, diodes, LEDs and much more. Unless you are using an advanced iron, as preferred by electrical engineers, you will most likely have no switches or controls (with the possible exception of temperature control). That's fine. Most people don't need any. Just put it into its stand and plug it in. It will start heating up immediately. You can find out if it's hot enough to use by touching the end with your solder. If it melts, it's ready.
Although simple in theory, soldering has a bit of a knack to it, so you might need to practice a few times before you get a good join. Check out the video below for more information.