What feature does JavaScript provide on web pages?

JavaScript is a versatile programming language primarily used for enhancing web pages by providing dynamic behavior and interactivity. This means that it allows developers to create elements on the page that can respond to user actions, such as clicks, form submissions, and other events, enabling a more engaging user experience.

This interactivity can include various features, such as updating the content without requiring a full page reload, validating user input, creating animations, and responding to user-initiated events in real time. These capabilities distinguish JavaScript from other technologies that might contribute to web development, such as HTML for structure or CSS for styling, which do not inherently provide dynamic functionality.

The other choices reflect features that do not align with the primary capabilities of JavaScript. Static content generation refers to content that does not change in response to user input, basic layout control pertains to CSS, and server-side data handling is typically managed by server-side programming languages rather than JavaScript running in the user's browser. Thus, the ability of JavaScript to introduce dynamic behavior and interactivity is what clearly sets it apart in web development contexts.