order book

An order book is a business's list of open, unshipped, customer orders, normally time-phased and valued at actual individual order prices, that may include margin and profitability analysis.

An order book is the list of orders (manual or electronic) that a trading venue (in particular stock exchanges) uses to record the interest of buyers and sellers in a particular financial instrument. A matching engine uses the book to determine which orders can be fulfilled i.e. what trades can be made.