Search engine spiders visit the site will be the first to visit robots.txt file, robots.txt is used to guide the search engine spiders to prohibit the capture of certain content on the site or only allowed to capture the content, placed in the root directory of the site. User-agent indicates that the following rules apply to which spider, * table ...

Unique H1 title Every page should have a unique h1 title, but not every page's h1 title is the site name. (But in html5 the h1 title is allowed to appear multiple times, and each tag with a structural outline can have its own independent h1 title, such as header,foote...