Domain name registrations are priced on a subscription-like model that allows a person or business to register that domain name for a certain period of time (usually in annual increments). At the end of the registration period, you (the domain name registrant) have the option to renew the domain name registration for an additional period of time, or let it expire. It is important to renew your domain name registration, or you may find that all of your work building traffic and views to your site ends up benefiting someone else (in the instance that someone else registers your domain name after you let your registration expire), and potentially costing you more in rebranding.
Second-level (or lower-level, depending on the established parent hierarchy) domain names are often created based on the name of a company (e.g., bbc.co.uk), product or service (e.g. hotmail.com). Below these levels, the next domain name component has been used to designate a particular host server. Therefore, ftp.example.com might be an FTP server, www.example.com would be a World Wide Web server, and mail.example.com could be an email server, each intended to perform only the implied function. Modern technology allows multiple physical servers with either different (cf. load balancing) or even identical addresses (cf. anycast) to serve a single hostname or domain name, or multiple domain names to be served by a single computer. The latter is very popular in Web hosting service centers, where service providers host the websites of many organizations on just a few servers.
The suffix identifies the name as belonging to a specific top-level domain (TLD). As of late 2016, when this article was written, there are numerous TLDs available for general purchase, including .com, .edu, .game, .green, .hiphop, .net, and .org. The most popular of these by far is .com, which is supposed to indicate commercial sites, but in reality has come to include almost everything.
Name servers. Most registrars provide two or more name servers as part of the registration service. However, a registrant may specify its own authoritative name servers to host a domain's resource records. The registrar's policies govern the number of servers and the type of server information required. Some providers require a hostname and the corresponding IP address or just the hostname, which must be resolvable either in the new domain, or exist elsewhere. Based on traditional requirements (RFC 1034), typically a minimum of two servers is required.
Who is in charge of all of these processes? Most countries manage a Network Information Center (NIC). An NIC is the main database that has all the information regarding what domain names have been registered and the IP address associated with each of those domains. The nonprofit organization the Internet Corporation for Assigned Names and Numbers (ICANN) is in charge of creating and managing the procedures for internet namespaces.
If you’re still with me then you might be wondering who came up with all of this. The answer is ICANN — the Internet Corporation for Assigned Names and Numbers. ICANN is a non-profit whose role is to coordinate all the names and numbers that keep the Internet online. They outsource a lot of the heavy domain name lifting to registries like Verisign, who pay ICANN for the privilege.
In order to register any domain, you must provide certain personal information that you may not wish to be publically searchable in the Whois database. Signing up for WhoisGuard is a great way to keep your registration data private. WhoisGuard acts as a "shield" for your searchable information, displaying the address, phone number, and email of the domain registrar (Namecheap, e.g.) instead of your own. Keep in mind that WhoisGuard is an optional security add-on that must be renewed separately when you renew your domain.