I am querying Broker database to get some metadata information. I am using Entity framework to communicate the database which is not recommended for broker database queries, I want to replace this functionality with "Broker Database API".

* Where can I find broker database API?
* Is there some set of dlls I need to import into my project?
* How will it interact with broker database? I need a connection string?

I found [following](http://vadalis.com/custom-meta-query-from-tridionbroker-database/) article on how to get information from broker database but does not explain where the dlls are? does not say where is connection string.
I have Tridion.ContentDelivery.dll in my application's bin folder, Is that Broker database API?