google site categories

Hi everyone, i am fairly new here.
Sometimes when i google for something, the top site in the results will be linked, and have sub-categories to various other parts of the site, even including a search box.
Not sure what the official name for this feature is.

I am writing small niche websites with few articles and a blog.
How can i make google give categories like that to my site?
Do i need a special wordpress plugin? Do i need to give tags to my blog post? Categorize my blog posts? etc..

Sorry about this basic question...

Its not something you can do with a plug in, its something google does themselves i believe.


Hopefully someone will come along that knows more about it than me.