👉 A two-decker is a type of deck in which each level has two floors. This means that there are two levels on one side and one level on the other, with no gaps or interruptions between them. The word "two" refers to the number of floors on each level, while "deck" refers to a surface used for transportation, typically on land. For example, a two-decker bus could be a bus that has two rows of seats on each side, with one row being