Top-Level Domains appear on the right-hand side of the dot in a URL. If you load a homepage of a website, it’ll often be the final letters presented after the dot. There are many types of TLD, but the most common are Country Code Top-Level Domains (ccTLDs) and generic TLDs.
ccTLDs include .uk and .de which denotes that the website is owned by an individual or organisation in the UK or Germany respectively. Meanwhile, generic TLDs include .com and .net, as well as .org and .digital. When selecting a URL for a website, webmasters will be required to select their TLD too.