Node.js: What is the difference between module.exports and exports in Node.js?

module.exports — actual export object. exports — reference to module.exports.

module.exports:

• The actual exported object.
• Can be any type (object, function, class).
• Replaces entire export.

1// Export function
2module.exports = function() {
3    return "Hello";
4};
5
6// Export class
7module.exports = class MyClass { };

exports:

• Reference to module.exports.
• Can add properties.
• Cannot reassign.

1// Add properties
2exports.hello = "Hello";
3exports.goodbye = "Goodbye";
4
5// This WON'T work!
6exports = { hello: "Hello" };  // Breaks reference

Key rule:

• Use exports for adding properties.
• Use module.exports for reassigning.