From Traderpedia

Definition: The active trading area of a stock or futures exchange, such as the New York Stock Exchange (NYSE).

Historically, securities and futures were traded auction-style on an exchange trading floor using the open outcry means of price discovery. That means the prices are set by competitive bidding between brokers, following a series of clearly established exchange rules.

Many brokerage firms that are market makers also refer to the space they have allocated for trading as their trading floor. The same term is used to describe the trading areas in banks and trading arcades.