Is cumin the same as black cumin or black seed?
No. Cumin is Cuminum cyminum; black seed is Nigella sativa from a different plant family.
The short answer
Cumin is an Apiaceae plant whose narrow brown ridged fruits are used as spice. Black seed or black cumin commonly refers to the angular black seeds of Nigella sativa in the Ranunculaceae family. Their chemistry, traditions, safety and research should not be transferred between cards.