Final answer:
Turnaround documents are considered an output device that facilitates interaction between humans and computer systems. They are essential for handling transactions efficiently in businesses. The microprocessor is the device that significantly increased the processing capabilities of digital computers.
Step-by-step explanation:
Turnaround documents are an example of a output device. These are documents that are created by a computer system, often as output from a transaction, and are designed to be read by both humans and machines. An example of a turnaround document could be a utility bill that includes a perforated payment slip which the customer returns with their payment. Once received, the payment slip can be fed back into a computer system to update the customer's account. This process is efficient for handling large volumes of transactions and is integral to many business operations.
The device that made it possible for digital computers to efficiently process large amounts of information is the microprocessor. This small, integrated circuit significantly advanced the capabilities of digital computers by increasing processing power and allowing for the development of personal computers, which could then be used in businesses and homes alike.