The world is filled with myriad pieces of data. From the color of your car to the number of dollars in your bank account, data are everywhere. Let’s call each piece of data an element. A single element, by itself, is not very interesting because there isn’t anything to compare it to, but elements are the building blocks for the more complex data structures I will discuss later on in this book. When a group of elements is arranged into a structure, the elements together can be called a data set.