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关于域名

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既然您拥有了域名,您就需要了解域名的基本情况及其如何与域名系统 (DNS) 融为一体。

单击此处了解有关域名行业中各种参与者的更多信息。

域名系统 (DNS) 可帮助您在互联网上确定自己的位置。互联网上的每台计算机都有一个唯一的地址。该地址是一串非常复杂的数字,称为"IP 地址"(IP 代表"互联网协议")。IP 地址很难记住;因此,DNS 使用常见的字符串("域名")代替了复杂的 IP 地址,进一步简化了互联网的使用。

DNS 域名的另一个特征是其层级结构。这体现在域名的构成中。例如,域名"whois.icann.org"有三个层级:"org"是第一级,"icann"是第二级,"whois"是第三级。值得一提的是,域名最多可以有 128 个层级!

正如用户看到的那样,域名的每个层级都由一个点隔开。在每个点处,可以将管理权限(即在该层级或以下层级中创建、编辑或删除域名的权力)分配或授权给另一方。继续以"whois.icann.org"为例:

  • ICANN 社群制定了创建、编辑或删除顶级域的规则;
  • 运营"org"顶级域的组织制定了在"org"内注册域名的规则(即注册政策);
    以及
  • 注册了域名"icann.org"的 ICANN 组织为"icann.org"下的域名制定规则,并使用这些规则创建了域名"whois.icann.org"。

因此,在您注册域名时,您在 DNS 中创建一个新的域,并赋予该域一个名称,这就是您注册的域名。

在这个新域中,您可以做很多事,比如为使用您注册的相同域名的网站创建域名或子域名。例如,如果您注册域名"example.com",您可以创建一个网站,并将其托管在 example.com、cookies.example.com 或 candies.example.com 上。您还可以使用域名来设置电子邮件地址,比如:cookies@example.com

域名并不是网址或统一资源定位符 (URL)。有一些人想当然地认为创建域名就意味着拥有网站,但他们不知道域名就像是收到邮件的街道地址:我们仍然需要提供相关的建筑或邮箱才能收到信件或包裹。您必须购买、寻找或部署网络托管或电子邮件等服务,使他人能访问和使用由您的域名指代的互联网地址。

常见问题与解答

Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as""icann.org"" is not an IDN."