JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy to read and write for both humans and machines. It is widely used in APIs, configuration files, and data storage due to its simplicity and flexibility.

JSON is based on key-value pairs, making it similar to a dictionary or an object in most programming languages. The format is language-independent but widely supported across various programming environments.

One of the biggest advantages of JSON is its compatibility with JavaScript, as it can be easily parsed and manipulated within web applications. This makes it a preferred choice for transmitting data between a server and a client.