What is a domain?
A domain name also referred to as domain name, domain name, is used for IP address (Internet Protocol) on behalf of the name, which is convenient for people to remember. An IP address is a unique string of numbers that identifies each computer's location on the Internet, like an address or phone number. However, this string of numbers is not easy to remember, and it is not convenient for the dissemination and use of the website. So DNS (Domain Name System) was developed as a distributed database that maps domain names and IP addresses to each other. DNS allows people to replace the original string of numbers with text names. It is much more convenient to use. You can think of DNS as the address book of your mobile phone. When you want to make a call, you just need to press the name of the contact and you can make a call without having to enter the phone number directly. The root domain of a website consists of a top-level domain (TLD) and a sub-domain (SLD), which is the domain used by the entire website, and under the root domain, you can create subdomains with various themes. The hierarchy of domain names gradually decreases from right to left, just like the structure of folders generally goes down. The concept of subdomains is relative, for example, www.example.com is a subdomain of example.com, which in turn is a subdomain of the top-level domain .com.Among the top-level domains (Top-Level Domains, TLDs)
The secondary domain name (Second-Level Domain)
The secondary domain name is the second-level structure in the domain, located on the left side of the top-level domain name. The combination of the top-level domain name and the sub-domain name (ie the root domain name) must be registered with the domain registrar. After registration, it will become a unique website address. In the example below, the subdomains are those shown in bold: www.wikipedia.org _ _ www.seoseo.com.tw _ _ tw.yahoo.com _ _Root Domain
Root domain usually refers to a combination of unique sub-domain and top-level domain names used to represent the address of the entire website. The root domain will be the highest-level page in the website structure. Under the root domain, you can create various subdomains or webpages, but technically, the URL corresponding to each page will contain the root domain. Using the example above, the root domain is: wikipedia.org seoseo.com.tw yahoo.com No two different websites will use the same root domain, other than having different subdomains as different websites. Because of this feature, the root domain can be used to represent the entire website rather than individual pages, so some people use the number of root domains linking to a website as one of the SEO indicators.Subdomain Subdomain
is the domain name of the domain below the third level in the entire domain structure, which will be added to the left of the root domain in the URL. As mentioned in the top paragraph, the concept of subdomains is relative, so if you add a subdomain of the next level on the left, you will add a subdomain to the lower level. An example is as follows: Subdomain: blog.example.com (third-level domain name: blog) Root domain: example.com Subdomain: www.example.com (third-level domain: www) Root domain: example.com Subdomain: en.blog.example.com (fourth-level domain name: en, third-level domain name: blog) Upper Domain: blog.example.comSEO Best Practices
(1) Pick an easy-to-remember domain name
If you want to pick a new domain name today, you should try to use the short, easy-to-remember, catchy, and easy-to-type domain name as your first choice. This practice is actually to make the website URL more easily spread out, and the things that can be easily read out have positive help for subsequent memory and use.(2) Are keywords used in domain names?
If putting keywords in your domain helps people understand your business while at the same time making it memorable, unique, and branded, then do it. But don't do it too deliberately, especially if you put too many keywords in it and it will look "unusual". While having keywords in your domain may be of little help, it's not worth the effort to convince users or search engines that your site is offering low-quality content or is not trusted. Let's see what Matt Cutts has to say about the choice to place keywords in the domain name: It is mentioned in the video that when picking a newly registered domain, you may have different strategies. One direction is to use branded words, such as Twitter, which are easy to remember but may not contain relevant keywords; another possible direction is to use relevant keywords in the domain, eg buyviagraonline.org. There are also differing views on which strategy should be the primary one. However, domain names that don't contain keywords have an absolute chance of success, and most of the time, those names that are familiar and well-known are names that don't contain keywords. The benefit of including keywords in the domain name is that it allows users to make associations with the content of the website when reading. But the problem that can arise is that if you have multiple different sites targeting the same keyword, placed on your domain, it will be harder to stand out and make a strong impression.At the end of the video, Matt Cutts mentions that Google has downgraded the importance of keywords in domain names in the algorithm (the film is set in 2011), so placing keywords in domain names may not be good for ranking Brings too much help.