For the most part, you can pick whichever TLD you prefer, though a few have restrictions -- you can't buy a .edu domain unless you run an accredited post-secondary school. Many, but not all, country-specific domains (.us, .uk, .jp) are restricted to citizens of the country in question. Unrestricted country domains are often used for "domain hacks," where the extension becomes part of the title, such as YouTube's alternate address, "youtu.be."
A domain name is, quite simply, the name of your website. The domain can be found in the URL and is used in order to locate the website of a specific person or organization. Each domain name or URL directs users to a specific IP address. Domains are easier to remember than a long and complicated IP address, which takes the form of a series of numbers. A domain can be divided up into three different elements: a subdomain, a domain name, and a top level domain (TLD). Take about.1and1.com as an example: the 'about' element is the subdomain, the '1and1' element is the domain name itself and the '.com' part of the URL is the top level domain. It is also possible to have multiple subdomain levels, info.about.1and1.com for example, which you can use to segment your website into separate categories. The length limit of a complete domain name is 255 characters. With 1&1, you can choose a domain name that best suits you or your business, or you can transfer an already existing domain over to 1&1. Next, customers can select a TLD from a wide variety of domain extensions on offer. When choosing a domain name, it is important to select something that properly reflects the ethos of your business in a concise and catchy way. A good domain should be memorable, brandable, and should have a suitable extension.
A domain name can be used for a variety of purposes. Many people who are not ready for a website simply register the domain name of their choice to ensure it doesn’t get snatched up by anyone else. They may use it to create a professionally branded email address, or as a Web address that can point customers to an alternate online presence, such as their social media page, if they don’t yet have a website.
Dotster.com — This registrar provides fairly cheap domain prices ($15.75 plus 20 cents per domain), a convenient web interface to manage your domains, an optional privacy facility where your domain name is registered in the name of a proxy company, etc. They offer .com, .net, .org, .biz, .info, .us, .ca, .tv, .name, .cc, .de, .sr, .md, .co.uk, .us.com domains, etc. If you're transferring a domain here from other registrars, the price is even cheaper ($6.99 plus 20 cents). Both credit card and PayPal payments are accepted here.
A handful of domains will have restrictions on them, which means you can only purchase them if you meet certain criteria or have authorization (some examples are .gov, .edu. and .mil). But most extensions are available to everyone. In fact, most country code Top Level Domains (ccTLDs) are available for anyone to purchase, even if you don’t reside in the country in question.