What is the criteria for approving a Blog Post

Question

I am a newbie to c-sharpcorner. I would like to know what are the criterias for approving a Blog.
Does a member can submit a blog for the topic which had been already approved in the site?

I saw a blog got approved today for the topic: Generics In C# With Example

When I searched the website for the posts on Generics, search returns lot of posts on Generics in C#. So I wonder why a new blog is being approved on the same topic again and again.

 

Can someone from Admin team clarify on this please?