The primary functions of a web browser include retrieving information from the internet, displaying web pages, and allowing users to navigate from one page to another via hyperlinks. Browsers interpret HTML, CSS, and JavaScript to render content visually. They also manage bookmarks, browser history, and settings to enhance user experience. Security features such as HTTPS support and pop-up blockers protect users from malicious content. Additionally, web browsers typically support extensions or plugins that can enhance functionality, allowing for a more customized browsing experience.