The definite article 'the' translates into German four ways:
der the is used for masculine nouns. The German word for masculine is männlich
die the is used for feminine nouns. The German word for feminine is weiblich
das the is used for neuter nouns. The German word for neuter is sächlich
die the is used for plural nouns. The German word for plural is plural
Note that in this, the nominative case, the words for the for plural and feminive are the same. This is not necessarily so with other cases. The nominative case is used with the subjects of sentences and with the verb sein.
The indefinite article 'a' translates into German three ways, using as a basis the number ein one:
ein a - männlich
eine a - weiblich
ein a - sächlich
Note that, as in English, there is no indefinite article for plural nouns.
Note also that while the männlich and sächlich words are the same in the nominative case, that will not always be so.