The so-called META tags are the tags that appear between the <head></head> tags in the website source code and contain the word "meta". Generally, META tags include three aspects: TITLE, KEYWORD, and DESCRIPTION. Among these, the TITLE is the title of the page, which is also what we refer to as the subject. The KEYWORD represents the page's keywords, and the DESCRIPTION provides a summary of the page. These three aspects are the first checkpoint when search engines crawl your page. Through them, the web crawlers can understand the relevant information and main ideas of your page.