From rack mounted units, and sound modelling to stomp boxes and effects pedals it is very hard to ply your trade as a guitar player without incorporating at least a few of these gadgets into your arsenal.
Distortion, compression, reverb, delay and chorus cover the basic sounds you will have to produce in most band settings. It is also important to learn how to get the best from these units when combining them in a chain or in the effects loop of your amplifier. There is seldom a completely optimised system when it comes to preserving the fidelity of your natural sound and maximising the flexibility offered through channel and effect switching, however there are many tips and suggestions which can help you get the best from your own set up.