Major Meta Tag :

Title tag
Description tag
Author tag
robots tag
googlebot tag etc...

Meta tags are snippets of text that describe a page's content; the meta tags don't appear on the page itself, but only in the page's code.
There are Lots Of Meta tag We Use.

Here are the some Important meta tags :-

Meta Keyword
Meta Description
Meta Title
Meta Author
Meta Content Type
Meta Robots
Meta Author
Meta Copyright

Four types of metatag is there inseo
Title tag
Description
Keyword
Robots

Meta tags are snippets of text that describe a page’s content; the meta tags don’t appear on the page itself, but only in the page’s code. We all know tags from blog culture, and meta tags are more or less the same thing, little content descriptors that help tell search engines what a web page is about.

The only difference between tags you can see (on a blogpost, say) and tags you can’t see is location: meta tags only exist in HTML, usually at the “head” of the page, and so are only visible to search engines (and people who know where to look). The “meta” stands for “metadata,” which is the kind of data these tags provide – data about the data on your page.

There are three main meta tags
1. Title Tag
2. Description Tag
3. Keyword Tag

Meta Tags
Robots Tags
Header tags H1, H2, H3
Alt Tags