What are the cases in German?

The cases help us to identify the noun's role in the sentence and make the article of the noun change depending on the case, gender and number. Nominative is the subject of the sentence (who's doing the action), the accusative is the object (the noun the action directly involves), the dative is the indirect object (for example, to whom the action is being done to) and the genitive, which is the least used case, indicates a possessive. As an example, 'Der Junge gibt dem Pferd des Mannes einen Apfel' - The boy gives the man's horse an apple. The boy is doing the giving so is in the nominative, the apple is being given so is in the accusative, the horse is receiving the apple so is in the dative and it belongs to the man so the man is in the genitive.