Soldering is fairly straightforward when you're attaching components to a board, but quickly becomes tricky when you need to solder components and wires with each other.
For situations like that, you'll need a tool called a "helping hand" to assist in the soldering process. It's job is to hold and align the components or wires that need to be joined, freeing up your hands to hold the soldering iron and the solder.
If you have actually tried this, you'll find that the whole process is quite finicky, especially the process of aligning the components or wires just right (making sure the leads are making proper contact) before you can apply the solder.
This is where the Fixed Soldering Iron Method comes in. It allows for a quick and easy way to solder wires and electronics components together.
Having the soldering iron fixed in-place frees up your hands, allowing better control and much more consistent results.