Continuous Trading

What Does Continuous Trading Mean?
A method of transacting different securities orders. Continuous trading involves the immediate execution of orders upon their reception by market makers and specialists.

Investopedia explains Continuous Trading
Unlike batch trading, which collects similar orders and executes them all at once, continuous trading entails the immediate placement of orders to market. In the U.S., all trades occur on a continuous basis except at opening.

For example, a limit order to sell a security is immediately sent to market and remains there until either the order expires or a buy order with a higher or equal buying price is sent to market.