HTML <meta> Tags encounter <meta http-equiv= "Refresh" content= "0; Url= "> Detailed

The page periodically refreshes, if added URL, will redirect to the specified page, content followed by the time (in seconds), add this sentence to the It is also commonly used in real-time applications where periodic refreshes are required.
such as news pages, forums, etc., but generally do not use this, all with new technology such as Ajax

Reference 1:100-degree library http://wenku.baidu.com/link?url=- 7vcmawxrrw1awwskfaekchunvgichrrrp-or30hfmomwhfocw-5smgy6bzzqkaqmb7d4c0i6i4mssw3yw1jzic6f3m9yvw585zobcwo4as

Meta is an accessible tag in the head area of the HTML language. In almost all pages, we can see the use of META tags in similar pages, keywords
The HTML code for the following paragraph: 
Reference two: W3school standard tutorial
Http://www.w3school.com.cn/tags/tag_meta.asp
HTML <meta> Tags encounter <meta http-equiv= "Refresh" content= "0; Url= "> Detailed