Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (ccTLDs). Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.

When you type into your browser, the domain is split into parts by the “dot”, from right to left. The first part is “com”, so your computer checks the root zone file to see which registry manages the .com TLD. It then checks with this registry to see where the next part, “google”, points to. The registry returns the IP address, and your computer can then ask Google to send their homepage over.
Classic domain extensions work for both options, as well as country specific extensions to build up local relevance. nTLD domain names such as .design, .business, or the eye-catching .nyc are good, .business especially in the case of a website builder package. There's often confusion surrounding the nTLDs, and it's good to know that the TLDs that imply a geographical reference are classified as generic top level domains by Google. For those who opt for website builder packages, it may be worth registering more than one domain extension, especially the classic extensions such as .com, as many users will remember this one better than the nTLDs – if you own the .com version but prefer the nTLD, you can always set up domain forwarding to avoid competition from other websites.
Premium domains (also known as aftermarket or pre-registered domains) are short domains, often just one word or even just 3-5 letters. Most of them have a .com extension but many premium domains end with .org, .net, and .biz. These domains include common words and are generally the most memorable. Because companies value short domains that match their company name or products, these domains are typically the most desirable. Additionally, certain domains sold by different registries are considered premium and therefore have a higher price point. In some cases, the renewal costs of these higher-priced domains are also quite expensive. Some high-priced premium domains, though, renew at a regular (lower cost) rate, giving you a better value in the long term. Make sure to research the overall cost of the domain plus renewal to find the right domain for your budget. You can browse Namecheap's premium domains in our Marketplace.