A web browser's main purpose is to act as a client application that requests web pages and other content from web servers, then interprets the code (like HTML, CSS, JavaScript) to display it visually for the user. Hosting websites (A) is the role of a web server, assigning IP addresses (B) is handled by network devices or protocols like DHCP, and while browsers support encryption (D) through HTTPS, that is a security feature rather than its fundamental primary function of content display.
