Final answer:
The missing component in a data communications network is a server, which works with a client and circuit to manage data flow. A microprocessor, which is an integrated circuit, is essential for processing large volumes of digital data.
Step-by-step explanation:
There are three basic hardware components for a data communications network: a client, a server, and a circuit. A server is a computer or computer program that manages access to a centralized resource or service in a network. The circuit, often in the form of an electrical pathway, facilitates the transmission of data between the client and server.
In the context of integrated circuits, devices like a microprocessor made it possible for digital computers to efficiently process large amounts of information by handling and manipulating data in the form of binary ones and zeros.