Domain names are used to identify one or more IP addresses. For example, the domain name microsoft.com represents about a dozen IP addresses. Domain names are used in URLs to identify particular Web pages. For example, in the URL http://www.pcwww.webopedia.com/, the domain name is pcwww.webopedia.com.
Every domain name has a suffix that indicates which top level domain (TLD) it belongs to. There are only a limited number of such domains. For example:
Because the Internet is based on IP addresses, not domain names, every Web server requires a Domain Name System (DNS) server to translate domain names into IP addresses.
Top Domain Name Providers
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1. Domain.com 
Domain.com has expanded from only offering domain name registration to offering a variety of web hosting services, such as shared, ecommerce, and VPS hosting options. Along with a 99 percent uptime guarantee and 24/7 customer support, Domain.com offers public access to a knowledge base that covers all the basics of hosting accounts, access, and passwords. Users can buy a domain name with a wide range of popular top level domains (TLDs) and over 25 country code top level domains (ccTLDs). Pricing starts with an entry-level package and ranges up to an ultra-level package.
2. Bluehost 
Bluehost is a website hosting and domain name provider that offers a full range of hosting and domain name services. It provides marketing training, SEO services, social media marketing, content creation, graphic design services, email, domain names, and local business listings. Bluehost is great for businesses of all sizes from new bloggers to established enterprises. Web pages are functional, stable, and attractive. Pricing is billed annually with four pricing tiers that increase in features along with the price.
3. Namecheap
Namecheap offers inexpensive domain names along with reliable service. Along with the ability to register a domain name and create an online identity, Namecheap offers shared, WordPress, reseller, VPS, and dedicated hosting services. Users get a secure, private email connected to their domain complete with business tools and calendar. Security features include two-factor authentication, low-cost SSL certificates, and PremiumDNS. Pricing for domain registration and hosting services is billed annually.
4. NameSilo 
NameSilo is a domain registration tool that focuses purely on domain registration and management. Registration is clean, fast, and easy. It offers free WHOIS privacy, API access, customizable packing options, and DNS management. If you already have an existing domain name, it can be transferred to NameSilo in exchange for a year added on to your expiration date included in your transfer price.
5. Hover
Hover makes it easy to find and register a domain name that works best for your business. It provides the tools needed to manage your domain, email, and DNS. WHOIS privacy is included with every domain name and security features such as two-factor authentication helps keep your domain safe. Professional email addresses can be added on with features such as private, add-free mail, mail forwarding, vacation autoresponder, and built-in anti-spam/virus.
6. Dynadot
Dynadot comes with a free website builder that allows users to build an attractive website upon registering a domain. Features include a control panel designed specifically for domain management, account security capabilities such as account lock and two-factor authentication, and a domain management API. The Dynadot Marketplace is great for users who are interested in buying, selling, or bidding on domains. Pricing is tier-based.
Related Webopedia Articles
Registering a Domain Name
Understanding Internet Governance
Countries and Their Domain Extensions
