Meta tags for search engines can be roughly divided into two types:

1) Meta tags for website optimization
These meta tags are used for SEO optimization of web pages by providing search engine crawlers with instructions for crawling and indexing, as well as information for determining relevance and generating SERP snippets.
2) Meta tags for site verification
These meta tags are used to confirm the site in the services for the webmasters of the Yandex and Google search engines.