subdomain.domain.topleveldomain

Examples:

www.google.com

www.google.es

mail.google.com

www.googlelabs.com

subdomain.domain.topleveldomain

The most common TLDs are:

• .com: "Commercial entities"
• .net: "Networking companies"
• .org: "Non-profits"
• .edu: US Education sites
• .gov: US Government sites

As .com, .net, and .org use isn't restricted, they are used more flexibly than as originally intended.

Each country has its own TLD (ccTLD), and they can decide who can register for domains with that TLD. Some also specify a set of "second-level-domain" for the TLDs.

• .us
• .fr
• .tv
• .uk (.co.uk)
• etc..

Most users expect to type in a .com domain, so you should always try to reserve that name (though it's often taken).

If you're worried about competitors, you should purchase related TLDs (.info, .net, .biz).

If your company targets a particular geographic market, it makes sense to get the ccTLD.

subdomain.domain.topleveldomain

The domain name must follow these rules:

• No spaces or underscores
• Dashes and numbers are OK

The domain name is not case-sensitive - google.com = GOOGLE.com.

A good domain name follows these guidelines:

• Represents your name or business name
• Short and memorable
• Easy to say aloud
• Easy to spell without mistakes
• Uses ASCII characters
• Doesn't infringe other's copyright

But good domain names are often taken. You can try using hyphens (experts-exchange.com) or making a TLD form part of the name (del.icio.us) to make it more likely the name will be available.

If you're having trouble thinking up a name, you can try NameTumbler, BustAName, Domainr, or just writing a bunch of keywords down and mashing them together in different forms.

subdomain.domain.topleveldomain

Once you own a domain name, you can make subdomains for different aspects of your product/company.

For example:

• www.twitter.com
• api.twitter.com
• search.twitter.com

You must use a "domain registrar" to purchase a domain. Consider these factors when picking one:

• Good customer service
• Easy-to-use admin interface
• Pricing (no hidden fees)
• Allows transfer of names to other registrar
• ICANN Accredited

The most popular registrar is GoDaddy, which offers good pricing and services but also tries to up-sell alot.

Other good registrars are:

• Domain.com: environmentally friendly
• NameCheap
• PairNic: "more expensive but more trustworthy"
• Name.com
• Hover: "clean and painless"
• DNSimple
• MyDomain
• HostGator
• NearlyFreeSpeech: pay as you go hosting

When you register, register the domain name for multiple years, and think about getting whois privacy to keep your contact details confidential.