https://www.tutorialspoint.com/html/html_meta_tags.htm
HTML lets you specify metadata - additional important information about a document in a variety of ways. The META elements can be used to include name/value pairs describing properties of the HTML document, such as author, expiry date, a list of keywords, document author etc.
The <meta> tag is used to provide such additional information. This tag is an empty element and so does not have a closing tag but it carries information within its attributes.
You can include one or more meta tags in your document based on what information you want to keep in your document but in general, meta tags do not impact physical appearance of the document so from appearance point of view, it does not matter if you include them or not.
Adding Meta Tags to Your Documents
You can add metadata to your web pages by placing <meta> tags inside the header of the document which is represented by <head> and </head> tags. A meta tag can have following attributes in addition to core attributes ?
Specifying Keywords
You can use <meta> tag to specify important keywords related to the document and later these keywords are used by the search engines while indexing your webpage for searching purpose.
Example
Following is an example, where we are adding HTML, Meta Tags, Metadata as important keywords about the document.
<!DOCTYPE html>
<html>
<head>
<title>Meta Tags Example</title>
<meta name = "keywords" content = "HTML, Meta Tags, Metadata" />
</head>
<body>
<p>Hello HTML5!</p>
</body>
</html>
Document Description
You can use <meta> tag to give a short description about the document. This again can be used by various search engines while indexing your webpage for searching purpose.
