One of the fundamental variable types, yet one of the more complex when you are beginning, is the Array. The array just takes a little bit to wrap your mind around, or maybe a good analogy as to exactly what it is doing.
You can pretty much think of an array as a mini-storage unit for variables, someplace to order them, keep them in one space, and reference them by name dynamically. There are more advanced ways to do some of this as well but arrays are a good starting point.