Every time you visit a website, your browser, the 'client', sends a request over the internet to a server, a computer that stores the website's files, which sends back the files needed to display the page; this request-response pattern uses a protocol called HTTP, or its secure version, HTTPS. A domain name is a human-readable address that points to a server's numeric IP address, while web hosting is the service that actually stores and serves the website's files to visitors. Websites are generally split into the front end -- everything the user sees and interacts with in the browser, built with HTML, CSS, and JavaScript -- and the back end, the server-side logic and databases that process data and business rules; this course focuses on front-end fundamentals.