1. From the perspective of URL, the secondary domain name is more trustworthy than the secondary directory in essence. However, from the perspective of search engine ranking, it is recommended to use subdirectories instead of secondary domain names as much as possible.

2.二级域名和一级域名是两个完全不同的网站，相当于两个要推广的网站。所有网络营销工作都必须再次进行。网站的公关价值和信任度将被这两者分开。该站点是分散的。使用二级域名将增加网站的数量，但同时会使网站变小。子目录将使网站变得越来越大。搜索引擎优化的非常重要的一点是网站的内容以及网站本身的质量和实力。网站的大小是重要的指标之一。

2. The secondary domain name and the primary domain name are two completely different websites, equivalent to two websites to be promoted. All network marketing work must be carried out again. The public relations value and trust of the website will be separated by the two. The site is decentralized. Using secondary domain names will increase the number of websites, but it will also make the website smaller. Subdirectories will make the website bigger and bigger. A very important point of search engine optimization is the content of the website and the quality and strength of the website itself. The size of the website is one of the most important indicators.

3.对于搜索引擎，第二级域名属于一个独立的网站，而子目录实际上属于主网站下的一个页面。 二级域名和子目录的权重较高。从理论上讲，二级域名和子目录在搜索引擎上的权重不高不低，但是对于不同的情况它们是不同的。对于新创建的子目录和二级域名，子目录更为重要，因为它们将继承主网站的权重。对于搜索引擎，它与网站上的其他页面没有什么不同，并且将很容易被包含；

3. For search engines, the secondary domain name belongs to an independent website, while the subdirectory actually belongs to a page under the main website. Secondary domain names and subdirectories have higher weights. Theoretically, the weight of secondary domain names and subdirectories in search engines is not high or low, but they are different for different situations. For newly created subdirectories and secondary domain names, subdirectories are more important because they will inherit the weight of the main website. For the search engine, it is no different from other pages on the website and will be easily included;

二级域名起初非常重要，因为二级域名相当于一个新网站，除非主域名很高，所以二级域名基本上类似于一个新网站。如果它想被搜索引擎包括在内。换句话说，子目录起初会比二级域名更好，但它们可能会朝相反的方向发展。

The secondary domain name is very important at first, because the secondary domain name is equivalent to a new website. Unless the primary domain name is very high, the secondary domain name is basically similar to a new website. If it wants to be included by search engines. In other words, subdirectories will initially be better than secondary domain names, but they may develop in the opposite direction.