SpecificFinder vs Finder in Business Data Connectivity (BDC)

I was trying to find the difference between SpecificFinder and Finder. I am not going deep inside the subject in this article, but if you really need know more about it, please visit this MSDN article.

A SpecificFinder can return a single entity instance by creating a Specific Finder method. The Business Data Connectivity (BDC) service executes the Specific Finder method when a user selects an entity in a Business Data Web Part or External list.

Anyway, the issue here is that we can use Finder as well… so what is the difference. Well, I will go deeper and deeper in this subject…but there is a superb explanation from Jonathon Palmer, so if you don’t mind I am going to reuse it.

- SpecificFinder is meant to find "one specific  instance" of the entity:

Customer GetCustomer(int id);

- Finder is meant to find "zero, one or more instances" for an entity:

Customer[] GetCustomers(string filter);