I've been doing a lot of research lately into domain names. Probably more than I should have been. I thought I'd write a guide on it for anyone who was interested. What are domain names? Domain names are addresses you can go to on the internet. Most addresses are stored as numbers. Those numbers are converted into "domain names" to make them easier for people to remember. For example 126.96.36.199 is converted into google.com, so you can access the site by typing the domain. Who can get a domain name? Anyone can get a domain name, but some Top level domains (TLDs) are only available to certain people. Domains are given out on a first come, first serve basis. So very generic names like books, videos, music, games, etc. were taken up quickly. Domains may be re-sold, resulting in many people buying up lots of domains and re-selling them. How does the domain process work? The most widely used domains are "top level" domains. These are typically three or four letter domain extensions administered by The Internet Corporation for Assigned Names and Numbers (ICANN) ( .travel and .museum being the only top level domains that are longer). ICANN draws up contracts with "registrars" which allows them to sell domains to individuals. For every domain a registrar sells, they pay a fee to ICANN, that fee is passed onto the consumer. So the registrar acts like a middle man, in the same sense that a super market is a middle man for product suppliers. What kind of domains are there? The domains that ICANN administers are as follows. Domains that can be registered by anyone. .com The most widely recognized extension on the internet. Intended for commercial entities, but were used so frequently they became the "standard" domain. Can be registered by anyone. .net Intended for internet service providers, but recently has become an alternative to .com domains. .org Intended for non-profit organizations. One of the more popular extensions. . .info Intended for sites providing information, but has frequently been used as an alternative to .com domains. They're very cheap, and generally avoided. .biz Intended for business organizations. .name Intended for individuals to use. Like JohnSmith.name . Domains are only intended to be registered by people with the name they're trying to register. Example: Joe registering Joe.name Top level domains only certain people can get. .aero For airlines. .asia For individuals or companies in Asia or Australia. .cat For websites in Catalan language, or relating to Catalan culture. Use of these domains for the English animal cat is not allowed. .coop For cooperative organizations. .edu For educational use. Widely owned by colleges and universities. .gov For the United States government. The United States is the only country with a top level domain. This is due to the internet being sponsored by the United States. .int For international organizations that are endorsed by a treaty by two or more nations. .jobs For companies with jobs to advertise. .mil For the United States military. Similar to .gov domains. .mobi For sites that are compatible with mobile devices. .museum For legitimate, verified museums. .pro For verified lawyers, accountants, physicians, and engineers in Canada, France, the UK and the US. .tel For Internet communication services. .travel For travel related sites. Country domains. Any verified country may request a domain extension from ICANN. Once ICANN grants the domains, the country can sell or give them out as they see fit. Countries can decide themselves on limitations. For example some countries require that your domain is a certain length. Some countries reserve certain domains and auction them off, or not allow anyone to use them. Some countries allow anyone to register their domains, and some require that you have a physical presence in their country. Some countries charge high amounts and some are cheap. Country domains are frequently used for "domain hacks". Where the last two letters of the domain are used to complete a word or phrase. Such as ga.me, love.ly, blo.gs, goo.gl Popular country extensions .uk Intended for the United Kingdom. .ca Intended for Canada. .tk Intended for Tokelau. These domains are being given out for free. .me Intended for Montenegro. Can be used for domain hacks, and are used by yahoo (me.me) facebook (fb.me) and wordpress (wp.me) for domain shorteners. .cc Intended for the coco islands. Commonly used due to their simple acronyms and reasonable price. .tv Intended for Tuvalu. Frequently used to associate itself with television. .de Intended for Germany. .cm intended for Cameroon. In 2006, the government created a wildcard redirect to redirect all unused .cm sites to a site with paid search links in order to generate revenue from people who misspelled domains (For example, google.cm) . Frequently associated with spam, and people trying to trick users to go to "look-a-like" domains. .cn Intended for China. .au Intended for Australia .us Intended for the United States. The United States government generally uses .gov however. Frequently used for domain hacks. .ru Intended for Russia. Frequently associated with spam. .jp Intended for Japan. .it intended for Italy. .fr Intended for France. .gs Intended for South Georgia and the South Sandwich Islands. Can be used for domain hacks. .no Intended for Norway. Other country domains. .ac, .ad, .ae, .af, .ag, .ai, .al, .am, .an, .ao, .aq, .ar, .as, .at, .aw, .ax, .az, .ba, .bb, .bd, .be, .bf, .bg, .bh, .bi, .bj, .bm, .bn, .bo, .br, .bs, .bt, .bv, .bw, .by, .bz, cd, .cf, .cg, .ch, .ci, .ck, .cl, .co, .cr, .cu, .cv, .cx, .cy, .cz, dj, .dk, .dm, .do, .dz, .ec, .ee, .eg, .er, .es, .et, .eu, .fi, .fj, .fu, .fm, .fo, .ga, .gb, .gd, .ge, .gf, .gg, .gh, .gi, .gl, .gm, .gn, .gp, .gq, .gr, .gt, .gu, .gw, .gy, .hk, .hm, .hn, .hr, .ht, .hu, .id, .ie, .il, .im, .in, .io, .iq, .ir, .is, .je, .jm, .jo, .ke, .kg, .kh, .ki, .km, .kn, .kp, .kr, .kw, .ky, .kz, .la, .lb, .lc, .li, .lk, .lr, .ls, .lt, .lu, .lv, .ly, .ma, .mc, .md, mg, .mh, .mk, .ml, .mm, .mn, .mo, .mp, .mq, .mr, .ms, .mt, .mu, .mv, .mw, .mx, .my, .mz, .na, .nc, .ne, .nf, .ng, .ni, .nl, .np, .nr, .nu, .nz, .om, .pa, .pe, .pf, .pg, .ph, .pk, .pl, .pm, .pn, .pr, .ps, .pt, .pw, .py, .qa, .re, .ro, .rs, .ru, .rw, .sa, .sb, .sc, .sd, .se, .sg, .sh, .si, .sj, .sk, .sl, .sm, .sn, .so, .sr, .st, .su, .sv, .sy, .sz, .tc, .td, .tf, .tg, .th, .tj .tl, .tm, .tn, .to, .tp, .tr, .tt, .tw, .tz, .ua, .ug, .uy, .uz, .va, .vc, .ve, .vg, .vi, .vn, .vu, .wf, .ws, .ye, .yt, .za, .zm, .zw. Domains that ICANN used when testing. Not available to the public. .xn--0zwm56d, .xn--11b5bs3a9aj6g, .xn--80akhbyknj4f, .xn--9t4b11yi5a, .xn--deba0ad, .xn--g6w251d, .xn--hgbk6aj7f53bba, .xn--hlcj6aya9esc7a, .xn--jxalpdlp, .xn--kgbechtv, .xn--zckzah .arpa A domain used for testing. The original domain name, that was eventually phased out by more popular domains (For example .com) What are the naming restrictions? There are certain limitations for what a domain name can be. Domains may not be longer than 63 characters. ICANN allowed 1 letter domains to be registered before 1993, before the internet was popular. After 1993, ICANN reserved all 1 letter top-level domains, but allowed ones that had previously been boughten to be "grandfathered" in. 2 letter domains were originally allowed, however were banned several years later in order to prevent people from getting them confused with country codes. Since this restriction was enacted long after the internet got popular, many 2 letter domains still exist. Like the 1 letter domains, they have been grandfathered in. Some exceptions to the 3 character minimum have been made for newer TLDs. Especially ones restricted to certain people. For example American Airlines was able to register aa.aero As far as naming policies goes, a domain may contain any numbers or letters. Uppercase and lowercase letters are not distinguished from each other. (So GOOgLe.com is the same as googLe.com) In order to allow more domain possibilities hyphens were allowed. A hyphen may not be used at the beginning or end of a domain. Two hyphens may not be used in a row. Countries have full authority over the length of the domains they give out (or any other restrictions, for example they can decide to block or auction off certain words). Some countries allow any length on a first come first serve basis. Some auction off 1-2 letter domains. Some charge higher fees for shorter domains. Some prohibit them altogether.