The function of a web browser is to retrieve, present, and navigate content on the World Wide Web. It interprets and displays HTML documents, allowing users to view websites, interact with various media types, and perform online searches. Browsers facilitate user interaction with web applications, support plugins, and manage tabs for multitasking. Modern browsers also focus on enhancing security through features like pop-up blockers and encryption. Moreover, they allow bookmarking for easy access to favorite sites, contributing to a seamless browsing experience.