HTML is a markup language that allows for the creation of web pages that can be viewed on the World Wide Web. It uses tags to add formatting and links to text. HTTP is the application protocol that governs how data is requested and transmitted between clients and servers on the web. Web browsers act as HTTP clients that send requests to server machines, which then process the requests and return the requested files. This allows for the navigation of web pages through links and surfing the web to find information.