What is the main function of JavaScript in web development?

JavaScript plays a pivotal role in web development primarily because it is designed to add interactivity and dynamic content to websites. This scripting language enables developers to create engaging user experiences through features like animations, form validations, interactive maps, and real-time updates. By manipulating HTML and CSS dynamically, JavaScript allows the page to respond to user actions, thereby enhancing user interaction. This ability to execute code in response to events (such as clicks or keystrokes) is what makes web applications feel alive and responsive.

Other options refer to functions that are either outside JavaScript's core capabilities or are typically handled by other technologies. For instance, while JavaScript can interact with the browser's local storage to store data on the client side, this is a secondary function compared to its primary purpose of interactivity. Managing server-side logic is usually the domain of server-side languages like PHP, Python, or Node.js. Similarly, while JavaScript can send and receive data from a server, it does not directly facilitate database connections; this task is generally managed by server-side technologies or frameworks dedicated to handling such connections. Thus, the main function of JavaScript remains its ability to enhance web pages with interactive features and dynamic content.