The ability to create new, high-level data types and organize them into a meaningful class structure is called data abstraction. Data abstraction is at the heart of object-oriented programming. Once you model objects with real-world properties from the basic data types, you can continue creating, assembling, and combining them into more and more complex objects at will. Then you can use these objects as if they were part of the original programming language. You can do most of your coding in a high-level, real-world context (roll the ball, reverse the pen), instead of the typical low-level, built-in data-type format (using numbers, characters, and symbols) of conventional programming.