Independent site: a website with its own independent domain name on the Internet.

Independent domain name: a separate domain name exists, for example, there is a website www.163.com, where 163.com is an independent domain name;

There is also a second-level domain name, for example, if you open a blog on the 163 website, the URL is www.myboke.163.com, which is a second-level domain name.

The ranking of independent domain names on search engines is much better than that of second-level domain names. You can optimize independent domain names separately, but the premise is that independent domain names have to be purchased, while second-level domain names can be obtained without spending money. Many industry websites have second-level domain names for free when they register, such as Alibaba, Huicong, Bafang Resources, Yihubaiying, China Machinery Network, etc., all give away second-level domain names.