Can you explain how 'this' works in JavaScript?

The this keyword in JavaScript behaves differently from many other programming languages. It is a complex concept because it is dynamically scoped, meaning its value is determined by how a function is called, not where the function is defined. In the global scope, this refers to the global object (which is the window object in a browser environment). Inside a function, this depends on how the function is called. If a function is called as a method of an object, this is bound to the object. If a function is called as a regular function, this is bound to the global object or undefined in strict mode. In an event handler, this is set to the element that fired the event. When using constructors and prototypes, this is bound to the newly created object. The value of this can be explicitly set with call(), apply(), and bind().