JSON (JavaScript Object Notation) is a lightweight, human-readable data interchange format. It is used to represent structured data in a text-based format that is easy for both humans and machines to read and write. JSON is often employed in a wide range of applications and systems for several reasons:

1. Simplicity and Readability: JSON's syntax is straightforward and closely resembles data structures in many programming languages. This makes it easy to read and write, which is advantageous for developers working with data.

2. Data Structure Support: JSON can represent complex data structures, including objects and arrays, which can be nested to any level. This flexibility allows it to model a wide range of data types and hierarchies.

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

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

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 and 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.

10. Open Standard: JSON is an open, well-documented standard, and there are many libraries and tools available in various programming languages for working with JSON data.

JSON's simplicity, flexibility, and wide acceptance in the software development community have made it a go-to choice for data exchange, configuration settings, and data storage in a variety of applications and systems.