JavaScript is an object-orientated scripting language that is mainly used to create dynamic functions and interactivity on websites. Unlike Java, however, JavaScript is a client-side scripting language, which means that the code is executed on the user's computer and not on a server.

JavaScript is usually embedded in HTML pages or stored in separate files and executed by web browsers. It enables developers to process user input, dynamically update content and respond to specific user actions. By using JavaScript, websites can respond to user input and provide a better user experience.

Java, on the other hand, is an object-oriented programming language that is used for a variety of applications and at different levels, including server-side application development. Unlike JavaScript, Java is a compiled language, which means that the code is compiled into bytecode files that can be executed on any platform that has a Java runtime environment.

To summarise, although JavaScript and Java are both programming languages, they are used for different purposes and at different levels. JavaScript is primarily used for the client-side development of interactive web applications and websites, while Java is a more general programming language that is used for a variety of applications and at different levels.