Meta tags are meta (additional) information usually describing the page and its contents. This is generally for search engines to read and understand the content of your page.
1. Set the charset -
<meta charset="utf-8">
This will ensure that when you go for international character sets, you will not see gibberish. If you do not understand, safely use the above statement for any html page.
2. Set the author name
<meta name="author" content="<author name>">
It is learnt that this information can be helpful in identifying the original author of the content. Search engines do use this information.
3. Search Engine Optimization (SEO)
<meta name="description" content="The important keywords of your article should go in here, so that when a user searches on a search engine, the page rank and the probability of the search results displaying on top results increases."
4. Keywords
<meta name="keyword" content="HTML,CSS,javascript">
Keywords will help Search engines as part of SEO ( Search Engine Optimization ) filter your page when a user uses keywords to search their results. It is also recommended that these keywords be frequently used- not overused in the content of the page being displayed to allow search engine to consider the page and keywords relevant and move your page up the order.
5.Title tag
<title>Your page title</title>
Even though this is not part meta tag, it is worth mentioning that this tag also adds value when a user searches on a Search engine and is an important parameter for SEO (Search Engine Optimizer), a key placeholder.