In JavaScript, the `this` keyword refers to the object that is executing the code it belongs to. It represents the context of the function or method call and allows us to access properties and methods of that object from within a function.

The value of `this` depends on where it is used in the code. In the global scope, `this` refers to the global object (usually `window`, `global`, or `undefined`). Inside functions or methods, `this` refers to the context of that function or method, which could be a different object depending on how the function was called.

Inside event handlers, the value of `this` is set to the element that triggered the event. For example, if you define an event listener for a click event on an HTML element, the value of `this` inside the event handler will be the element itself. This allows you to access properties and methods of the element from within the event handler.

const myElement = document.getElementById('my-element');
myElement.addEventListener('click', function() {
  console.log(this.textContent); // logs the text content of the element
});

In this example, `myElement` is an HTML element and we are attaching a click event listener to it using the `addEventListener()` method. When the click event is triggered on the `myElement`, the `this` value inside the event handler will be set to `myElement`. We can then use the `textContent` property of the `myElement` to log its text content.