As we write code, we use and create abstractions constantly. Abstraction is what occurs when we take a piece of complexity and then present access to that complexity in a simpler way. By doing this, we enable people to have leverage over that complexity without having to wield a full understanding of it. This idea underpins most modern technology:

JavaScript, like many other high-level languages, presents an abstraction that enables us not to have to worry about the details of how a computer operates. We can, for example, ignore the problem of memory allocation. Even though we must be sensitive to the constraints of hardware, especially on mobile devices, we'll rarely ever think about it. The language doesn't require us to.

The browser, too, is a famous abstraction. It provides a GUI that abstracts away, among many other things, the details of HTTP communication and HTML rendering. Users can easily browse the internet without ever having to worry about these mechanisms.

In the following chapters of this book, we'll learn more about what it takes to craft a good abstraction. For now, it's enough to say this: in every line of code you write, you are using, creating, and communicating abstractions.