A process for achieving the extraction of relevant data while the related transaction or operation is occurring. An example is a supermarket checkout equipped with point-of-sale terminals. The transaction is primarily concerned with the sale to the customer but while the purchased items are being entered onto the bill it is usual for the machine to record, and thus capture, data that will allow calculation of stock movement and other information.

If the equipment for data capture is online to a computer system, it is part of a data collection process and may be referred to as either data capture or data collection equipment. The term data capture is often used where a computer system monitors (and maybe controls) laboratory instruments, process parameters, etc.; in this context it is also known as data logging.