JavaScript is a versatile programming language used to create dynamic and interactive content on websites. It runs in the browser and can manipulate HTML and CSS, making webpages responsive to user actions.

Although they share a similar name, Java and JavaScript are distinct languages. Java is a full-fledged programming language used primarily for server-side and application development, while JavaScript is mainly for web development and runs in the browser.

this is a keyword that refers to the context in which a function is executed. In a method, it refers to the object the method belongs to; in a regular function, it refers to the global object (or undefined in strict mode).