(Guitar Reference). Strings are the most important part of your guitar. They are the source of the sound and are what you are actually playing. In this Riff Notes series book you'll discover everything you need to know about strings, so you can immediately get off to the right start, whether you are playing an electric or acoustic guitar. The two main types of strings, steel and nylon , are fully explored. Steel is metal and nylon is a stretchy plastic. Strings are either plain or wound, and this is how they are referred to when we are talking about a single string. Any guitar you buy comes with strings already on it but knowing all about them, what kind are right for your guitar, and how to maintenance and replace your strings is essential. All of this and more will be explained in this Riff Notes book.