Online processing is one of the way to process transactions in Transaction processing system (TPS).
Online transaction processing is the almost instantaneous processing of data. The term online means that the data input device is directly linked to the TPS and therefore the data are processed as soon as it is entered into the system.
The input device may be at a remote location and be linked to the system by networks or by telecommunications systems.
Data are processed as they are created; since there is no time lag between data creation and data processing, the information in an online system is always current.