W3C and Meta tag

If W3C validator did not validate the html document for no character encoding, this can be correcte by inserting a meta tag.
Meta tag? It means information about information. tags that are invisible to users but explain things to client apps
Meta elements are generally used to specify things such as keywords, author, last modified, and other metadata.
The meta tag always goes inside the head element. Search engines use meta data for example for keyword search.