JavaScript functions are a fundamental aspect of the language, enabling developers to group reusable code into modular blocks. A function in JavaScript is essentially a set of statements that perform a specific task or calculate a value. You define a function with a name, a list of parameters (optional), and a block of code that executes when the function is called. Functions allow for better organization and reuse of code, reducing redundancy and improving maintainability.

Events in JavaScript refer to the interactions that occur in a web page, such as clicks, key presses, or form submissions. JavaScript allows you to handle these events by attaching event listeners to HTML elements. When an event occurs, the corresponding event handler (a function) is executed. This mechanism enables dynamic and interactive web applications, as developers can respond to user actions in real time. For example, you might use an event listener to execute a function when a button is clicked, changing the content of a webpage or submitting data to a server.

Together, functions and events are crucial for creating interactive and efficient web applications, enabling developers to build responsive user interfaces and manage complex behaviors with ease.