Module 03: Domains, DNS, and Hosting

A Content Delivery Network is usually called a CDN. A CDN is a network of servers placed in different locations so website content can be delivered faster, more reliably, and sometimes more securely.

This section explains several common types of web hosting: shared hosting, VPS hosting, dedicated hosting, cloud hosting, serverless hosting, managed hosting, and static site hosting.

Web hosting is the service that makes a website available on the Internet. When someone creates a website, the website’s files need to be stored somewhere. These files may include text, images, videos, HTML, CSS, JavaScript, documents, application code, and database information.

A domain name by itself is not enough. A domain needs records that explain what should happen when someone tries to use it. For example, DNS records can answer questions like: Where should the website load from? Which server handles email for this domain? Which servers are allowed to send email for this domain?

When someone types a domain name into a browser, the browser needs to find the technical information connected to that name. This process is called a DNS lookup. A DNS lookup is the process of finding the DNS information connected to a domain name.

Domain names give people a readable way to find websites and online services. People type names like google.com, wikipedia.org, michaelisuniversity.com. Computers, however, still need technical information in order to make the connection.

The Internet connects computers, phones, servers, and other devices around the world. For these devices to communicate, they need addresses. These addresses are called IP addresses.

Module 3 explains how domain names, DNS, hosting, and CDNs work together to make websites reachable on the Internet. It begins by showing that domain names are human-readable names that point people toward online services, while DNS is the system that translates those names into the technical information computers need. The module then explains how DNS lookup works, including resolvers, root servers, top-level domain servers, authoritative name servers, caching, and DNS records such as A, AAAA, CNAME, MX, TXT, and NS records.