Book excerpt: JSON (JavaScript Object Notation) is a lightweight text-based data interchange format used to create objects to transfer data over the Internet. It's widely used today by common web applications, as well as mobile applications. This book gives you clear ways that you can exchange objects using JSON, regardless of whether you're developing a web or traditional networked application. You'll start with a brief refresher on JSON and JavaScript syntax and read and write on the client and server. Then, you'll learn how to use JSON in simple AJAX applications using AngularJS and jQuery. Next, you will learn how to exchange objects with databases using MongoDB and CouchDB. You'll also explore how to use JSON in a type-safe manner, writing programs that have fewer bugs.