What is the purpose of the 'require' function in Node.js?

The 'require' function in Node.js serves the purpose of including modules in an application. Node.js operates on a module system that allows developers to separate their code into different files and reuse code across applications efficiently. By using the 'require' function, you can import built-in modules, third-party libraries, or your own custom modules. This modular approach helps in organizing code, reducing redundancy, and enhancing maintainability.

For instance, if you have a utility function defined in a separate file, you can include it in your main application file using 'require', which brings that functionality into the current scope. This feature is fundamental to Node.js's architecture and allows developers to leverage a wide range of modules available in the Node.js ecosystem or their own reusable code structures.