Cards and Plug-in

Cards noun - A game played with playing cards.

Plug-in is a synonym for cards. In some cases you can use "Plug-in" instead a noun "Cards".

Plug-in noun - A printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities.

Cards is a synonym for plug-in. Sometimes you can replace term "Cards" with "Plug-in", this terms are similar.