There are many different types of electrical boxes.
Some are designed to house switches and outlets, while others are used for hanging light fixtures. Still others are designed for outdoor and whetherprrof installations, not to mention low-voltage installations.
If you're installing electrical boxes in concrete or bricks, there are special boxes for this also. If you know what type of box to use, how to install it, and what to use to cover them, you'll be on your way to successfully