What is the use of tags in content and SEO?

[Fidelia]

I see that in many contents written on writing sites, writers are prompted to add tags and meta tags to the contents. For some article sites, they won't accept your contents if it doesn't have tags.

What is the use of tags and Meta tags in contents and SEO?

 

[Nomad]

Tags work as keywords. These tags help search engine bot to understand what your content is all about.