What is Deck ?
Deck is (noun) 1. a floor of a ship or bus I’ll stay on deck because I’m feeling seasick. Let’s go up to the top deck you can see the sights better from there. 2. US a set of playing cards She shuffled the deck. (NOTE: The British term is pack of cards.) 3. US a wooden platform on the outside of a house We had drinks outside on the deck. 4. an apparatus for playing cassettes
source: Easier English, Student Dictionary Upper Intermediate Level