Helping people with computers... one answer at a time.
A concept we often take for granted is that of internet domains, and how they're purchased and set up for use. I'll look at what it's all about.
What is the concept of domains and domain registering?
Domain registration is something many people take for granted. Yes, it means ownership, of a sort, but it's also not really enough to just register a domain if you actually want to use it for something - you'll need to do more.
As I write this, I own something like 69 domains, so I know a little bit about what this is all about.
Let me walk you through the concepts.
First we have to clarify just exactly what this thing called a "domain" is.
At it's most basic, a domain is simply a name intended to be human readable that is associated with a number - an IP address - that is what computer's "really use" to talk to each other. There's more, of course, but that's the most basic concept.
"ask-leo.com" is a domain. It currently represents an IP address of 126.96.36.199. I say "currently" because that, of course, could change. That's another advantage of using domains over raw IP addresses - using the domain allows the IP address to change without you needing to care.
While the common terminology is that you "purchase" a domain, in reality it's more like you're leasing it. You retain ownership of a domain by paying an annual fee. Depending on the domain and the registrar, which I'll talk about in a moment, those fees can be as low as five or six dollars a year, or much higher. Most registrars also allow you to pre-pay, at a discount, for several years.
A "registrar" is a company that is authorized to register domains on your behalf, and sell them to you. One of the largest domain registrars is GoDaddy, for example. I happen to use SimpleURL.
Note that not all registrars can sell you all domains. For example, the popular ".com", ".net" and ".org" domains are commonly available through most US based registrars, but for foreign based domains such as ".co.uk", ".cn", ".to" and the like you'll often need to locate the registrar responsible for those "top level" domains, as they're called, and register with them.
As a side note, by default registration information is public. In other words, unless you take extra steps, or specifically request an anonymization service from your registrar, your name, email address and mailing address are all required to be public information. In fact, if you look at the registration information for ask-leo.com (scroll down once there) you'll see the type of information that's made available. Make sure that you understand what's being made public, and take appropriate steps to protect your privacy (as I have, using a post office box, and a voicemail only telephone number).
Once you've registered your domain you don't automatically get a working website or email. In fact, you often get absolutely nothing, except the ownership of the domain and the tools to allow you to make those IP address assignments.
That's where DNS comes in.
DNS, an acronym for "Domain Name System" (or Service) is the system and protocol that's used to map domain names to IP addresses and other information associated with the domain.
Every domain has associated with it at least one DNS Server - quite literally a server that is internet accessible that contains the authoritative reference of information for that domain. In addition to your registration information, your domain registrar must keep at least one piece of information about your domain that boils down to: "if you want to know anything about this domain, talk to this server over here".
The DNS Server does not have to be owned or controlled by your registrar - the registrar simply needs to point to it when asked about your domain. Again, if you look at the information for "ask-leo.com", even though it's registered via SimpleURL, the DNS servers listed are ns.rackspace.com and ns2.rackspace.com, as a backup. It's the ns.rackspace.com server that contains all the "what IP address does this domain refer to" information.
Most registrars will assign domains they register a DNS server of their own automatically. In most cases, that's actually just fine, and it may be required if you're using some of the registrars additional services I'll talk about in a moment. The important thing is that you have some kind of access to the DNS server's information so that you can control the settings associated with your domain.
Where email gets delivered for your domain goes is controlled by DNS. One of the bits of information in DNS about your domain is called an "MX" or mail exchanger record. This says simply "email for this domain should be routed to that server over there". It can, of course, point to a server you control, if you're running your own email server.
While that's what I do, I suspect that in most cases that's not at all what you want.
Many registrars offer email services for you as part of your domain purchase. Particularly if all you wanted the domain for is to have your own email address on that domain, those services are probably the way to go.
The services provided are at a minimum email forwarding - so you can, for example, set up email@example.com and have that automatically forwarded to your Hotmail, Gmail or other email account. Even better, when you decide to change from Hotmail to Gmail or something else, all you need do is change the forwarding rule at your registrar and firstname.lastname@example.org will automatically begin arriving at your new address without having to tell all your contacts that anything has changed.
Many registrars will also provide actual email mailboxes for you to directly access your email without forwarding it at all.
Web hosting is all about setting up a web site. It's actually completely separate from email, with the exception that it too starts in DNS.
As I mentioned, one of the basic uses of DNS is to map the name to an IP address - ask-leo.com to 188.8.131.52, for example. What that means is that when you request a page from ask-leo.com in your browser - say by visiting http://ask-leo.com - your browser first asks DNS "where's ask-leo.com?", gets the answer (184.108.40.206), and then connects to that server to fetch the pages that comprise the site.
That server is the "web host" - it's the server that holds the files that make up the web site.
There are several approaches to web hosting:
None. If all you want is email, you may not need a web host at all. If all you care about is that email@example.com works, then it probably doesn't matter that http://www.yourdomain.com doesn't.
Registrar provided. This is actually a special case of the next item, but has the advantage that you probably have the least to do. Letting your registrar not only do your DNS for you, but also host your website, is often the simplest approach to getting your website up. It's not always the most cost-effective, or most capable, but it is simple and often a great place to start.
Shared hosting. With shared hosting you contract with a provider to literally share some space on one of their servers - often with dozens or hundreds of other web sites. They give you a place to put your content (and often host your email), and all you do is point your DNS at the IP address of their server. Shared hosting is extremely common, and often very inexpensive - for example I often work with BlueHost, which at this writing offers a very nice and complete package of web hosting for $6.95/month. There are many other services in this space - as I said, it's extremely common.
Dedicated hosting. For high end or mission critical services, dedicated hosting is pretty much what it sounds like: you contract with a hosting provider for an entire server dedicated to whatever it is you want to do. While that's how Ask Leo! is set up, I'd not recommend it for average consumers or small businesses unless you had extraordinary needs. It can get pricey.
Host it yourself. I get questions about this all the time - people want to run a server at home. It's very possible, but typically not practical unless you're quite knowledgeable and happen to have a very good internet connection.
Pulling it all together
When registering a domain there are several aspects to consider:
Registering an available domain name itself.
Using DNS to make sure that the domain references the right servers and services.
Determining if and what email services to use, and how they should be provided.
Determining if and what website services to use, and how that should be set up.
For casual use, a single domain registrar can typically provide the entire set of services to get your domain up and running. As your needs and experience expand, you can pick-and-choose, moving different aspects of domain management to other services and providers as needed.