What is the difference between a first level domain name and a second level domain name?

A first-level domain name is like nothing in front of it, and a first-level domain name is a domain name.

Second-level domain name: It is common to add www in front of it, and you know that adding zhidao in front of the domain name is also a second-level domain name. Thank you!

The number of levels of domain names is to see how many are behind the domain name"."A delimited suffix.

For example: "fuyeor com" has a to:"."The delimited suffix is a first-level domain name, also known as a naked domain name. where com is the top-level domain, or also known as the root domain name or domain extension.

The second-level domain name is the domain name that is hosted under the main domain name, which is the domain name one level to the left of the naked domain name. Generally speaking, a second-level domain name is a format like 3 Ws (www).

For example: "www fuyeor com" has two or more options"."The delimited suffix is a second-level domain name.

Because IP addresses are boring, long strings of numbers, to make it easy to remember, you have domain names, such as: "second-level domain fuyeor root domain", or simply "fuyeor root domain" format without a second-level domain.

Among them, in the "second-level domain name fuyeor root domain name", fuyeor is the subject of the domain name; The root domain name is the suffixes com, net, and cn.

Level 1 is without www, such as: , also called top-level domain name. Level 2 is like this:

It doesn't matter if the domain name is good enough.

The differences are as follows:1. The domain name level is different.

First-level domain name. More advanced than the second-level domain name, the second-level domain name needs to be attached to the affiliated partition domain name under the first-level domain name, and the second-level domain name is also a complete domain name for users, after all, the second-level domain name looks more authoritative, and the second-level domain name is for search engines.

to talk about the topic more focused.

2. Different permissions.

The authority of the first-level domain name is more than the authority of the second-level domain name, and the second-level domain name has its own characteristics for some small aspects of control, although the first-level domain name can directly manage the second-level domain name, and the second-level domain name is included and snapshotted.

etc., these are independent idleness of the second-level domain name, and the second-level domain name cannot "access" the first-level domain name.

3. The penalties are different jointly.

When the first-level domain name is punished, the second-level domain name will also be punished, and when the second-level domain name is punished, the first-level domain name will not be affected, and the relationship between the first-level domain name and the second-level domain name is not complicated, but there are some details that need to be distinguished in detail.

**The differences between first-level and second-level domains are as follows1.The composition is not the same.

This can be intuitively seen from the domain name, the first-level domain name is composed of two or more words, separated by a period in the middle, and the entire domain name has only 1 period, such as, and the second-level domain name has 2 points, this way.

2.The hierarchy of domain names is also different.

The first-level domain name is also commonly known as the top-level domain name, as the name suggests, it must be more advanced than the second-level domain name, and the second-level domain name is the refinement and grading of the first-level domain name, generally speaking, the weight is lower than the main domain name, and it needs to rely on the first-level domain name, and if the first-level domain name disappears, then the corresponding second-level domain name does not exist, but if the second-level domain name ** does not do, the main domain name is not affected.

3.The permissions of the domain name are different.

The first-level domain name is the highest-level domain name partition, so it has all the subordinate second-level domain name area, modification, storage and other use rights, and the second-level domain name is an independent branch, although it also has its own collection, snapshot, PR value, backlink, etc., but it should be noted that the second-level domain name cannot access the first-level domain interval without approval.

1. The usage rate is different

The proportion of second-level domain names used is higher than that of first-level domains, and the PR value of second-level domains is often one notch lower than that of first-level domains.

2. The penalties are different jointly:

Usually, when a first-level domain name is penalized, the associated second-level domain name will be penalized, and if the second-level domain name is penalized, it will not affect the operation of the first-level domain name. From this point, it can be seen that the first-level domain name and the second-level domain name are better or worse, and being able to register or buy a first-level domain name by yourself is of course the best choice for webmasters.

3. Different permissions:

The first-level domain name is the highest-level domain name partition, so it has the right to use all subordinate second-level domain names such as region, modification, storage, etc. The second-level domain name is an independent branch, although it also has its own index, snapshot, PR value, backlink, etc., but it should be noted that the second-level domain name cannot access the first-level domain interval without approval.

The difference between domain names and second-level domain names is that they have different compositions, different scopes, and different functions.

First, the composition is different.

1. Domain name: A domain name is the name of a computer or group of computers on the Internet composed of a string of names separated by dots.

2. Second-level domain name: The second-level domain name is the penultimate part of the domain name, which belongs to the domain name separated from the main domain name.

Second, the scope is different.

1. Domain name: Domain name is mainly used for Internet infrastructure databases.

Third, the role is different.

The main differences between them are as follows:

1. The definitions are different.

Top-level domains (or top-level domains), English: top-level domains, first-level domains (TLDS), also translated as international top-level domains. It is the highest level of the Internet's DNS hierarchy;

Second-level domains (or second-level domain names; English: second-level domain; English abbreviation: SLD) is a domain in the Internet DNS hierarchy below the top-level domain.

The second-level domain name is the penultimate part of the domain name, for example, in a domain name, the second-level domain name is baidu.

2. The composition of domain names is different.

A first-level domain name is composed of a legal string + domain name suffix, for example: this form of domain name is the first-level domain name, and lisp is the body of the domain namecom is a domain extension and can be: .net is also a domain extension;

A second-level domain name is a hostname below a first-level domain name, which is preceded by a string at the first level of the domain name, for example.

3. Different classifications.

There are 4 main categories of top-level domains:

1) Generic top-level domain (abbreviated as gTLD), such as:".com"、"net"、"org"、"edu"、"info"etc., all of which are managed by foreign companies;

2) Country code top-level domain (abbreviated as ccTLD), such as:".cn"On behalf of China,".

uk"On behalf of the United Kingdom, for example, geotop-level domains are generally managed by individual countries or regions.

3) Infrastructure top-level domains (..)arpa, which has been included in the "gTLD" in the past);

4) Test the top-level domain.

Second-level domain names are further divided into two categories: category domain names and administrative region names

1) There are a total of 6 category domain names, including those used for scientific research institutions. ac；It is used in industrial and commercial financial enterprises. com；For use in educational institutions.

edu；For the ** sector. gov；It is used for Internet information centers and operation centers. net；For non-profit organizations.

org；2) There are 34 administrative region names, corresponding to all provinces, autonomous regions and municipalities directly under the central government in China.