SEO: the major role of small and medium-sized Meta in HTML documents

Meta is used to simulate HTTP Response Header packets in HTML documents. Meta Tags are used in Name attribute
<Meta name = "generator" contect = ""> describes generation tools (such as Microsoft FrontPage 4.0;

<Meta name = "keywords" contect = ""> describe keywords Of Your webpage to search engines;

<Meta name = "Description" contect = ""> tell the search engine the main content of your site;

<Meta name = "author" contect = "Your name"> tell the search engine the creator of your site;

<Meta name = "Robots" contect = "All | none | index | noindex | follow | nofollow">
The attributes are described as follows:
Set to all: the file will be retrieved, and the link on the page can be queried;

Set to none: files will not be retrieved, and links on the page cannot be queried;

Set to index: the file will be retrieved;

Set to follow: links on the page can be queried;

Set to noindex: the file will not be retrieved, but the link on the page can be queried;

Set to nofollow: files will not be retrieved, and links on the page can be queried.
HTTP-equiv attributes
<Meta http-equiv = "Content-Type" contect = "text/html "; charset = gb_2312-80 "> and <meta http-equiv =" content-language "contect =" ZH-CN "> describe the text and language used by the home page; also such as English is the ISO-8859-1 character set, there are big5, UTF-8, shift-JIS, EUC, Koi8-2 and other character sets;

<Meta http-equiv = "refresh" contect = "N; url = http: // yourlink"> regularly redirects a webpage to HTTP within the specified time; // yourlink;

<Meta http-equiv = "expires" contect = "mon, 12 May 2001 00:20:00 GMT"> this parameter can be used to set the expiration time of a webpage. Once it expires, it must be called on the server again. Note that the GMT time format must be used;

<Meta http-equiv = "Pragma" contect = "no-Cache"> This is used to disable the browser from accessing the page content from the cache of the local machine, once the page is set, it cannot be called out from the cache;

<Meta http-equiv = "Set-cookie" contect = "mon, 12 May 2001 00:20:00 GMT"> cookie setting: If the webpage expires, the cookie on the disk will be deleted. Note that the GMT time format must be used;

<Meta http-equiv = "pics-label" contect = ""> webpage rating, which has a content setting in Internet Options of IE, can prevent browsing some restricted websites, the website's restriction level is set through the meta attribute;

<Meta http-equiv = "Windows-target" contect = "_ top"> force the page to be displayed on an independent page in the current window, it can prevent your webpage from being called as a frame page by others;

and set the special effect when you enter and exit the page, this function is called "format/Webpage transition" in FrontPage, but the page to be added cannot be a frame page.