JSON (JavaScript Object Notation) is a lightweight data interchange format that is commonly used in web development. It is a text-based format for representing structured data. JSON has become popular for several key reasons:

1. Simplicity and Readability: JSON is easy for both humans and machines to read and write. Its syntax is straightforward and closely resembles data structures in many programming languages. This simplicity makes it an ideal choice for data interchange.

2. Data Structure: JSON supports the representation of complex data structures, including objects and arrays, which can be nested to any level. This makes it versatile for modeling a wide range of data types and hierarchies.

3. Lightweight and Fast: JSON is a lightweight format, which means it has a small footprint when transmitted over the network. Parsing and generating JSON is efficient and fast, making it suitable for web applications where speed and performance are crucial.

4. Native JavaScript Support: JSON is native to JavaScript, meaning JavaScript can easily parse JSON data using JSON.parse() and create JSON strings using JSON.stringify(). This close integration simplifies data handling in web development, where JavaScript is commonly used.

5. Human-Readable and Writable: JSON's human-readable format makes it an excellent choice for configuration files and data storage. Developers can work with JSON data directly without specialized tools.

6. Standardization: JSON is an open standard that is widely accepted and supported across various programming languages and platforms. This interoperability makes it a universal choice for data exchange.

7. Common Usage in APIs: Many web APIs use JSON as their data format for request and response payloads. This makes it easy for web developers to work with APIs and integrate external services into their applications.

8. Safe and Secure: JSON does not support executable code, making it a safer alternative to other data interchange formats like XML, which can carry potential security risks.

9. Versatility: JSON is used in a variety of contexts in web development, including configuration files, data storage, and AJAX requests. It is suitable for representing structured data, making it a versatile choice for developers.

JSON is commonly used in web development due to its simplicity, efficiency, and versatility. Whether working with APIs, managing configuration settings, or exchanging data between the client and server, JSON is a robust and widely accepted choice for representing structured data in a format that is easy to work with and understand.