SD/MMC Issues?

Greetings ALL,

New here so, bear with me until I get the hang of things here.

I purchase a Android tv box (KODI) and am awaiting it’s arrival. I have asked the seller what type of storage this unit will accept in the form of a card. His answer was non-specific to say the least. There is a slot on the rear panel of the unit. Please see the attached pict **ATTEMPTED TO ATTACH PICT BUT, SEE NO PLACE I CAN ACCOMPLISH THIS)** and notice that it says “SD/MMC” . Herein may lie my confusion.

If I understood/mis-understood the seller, he indicated that the unit may possibly NOT use sd ram (?). I attempted to read up on both “SD” and “MMC” prefixes and it appears that they are different in size and use. Can anyone help me out here on this?………Thanks.