What is the function of an external data bus?

The function of an external data bus is effectively to serve as a row of wires that interconnect various components of a computer system. It facilitates communication by allowing data to be transmitted between the processor, memory, and other peripheral devices. The external data bus plays a crucial role in ensuring that these components can exchange information efficiently, thereby enabling the overall functionality of the system.

In contrast to other options, a software interface typically refers to programs used to facilitate interactions between software applications, which is not the primary role of an external data bus. A type of storage pertains to components like hard drives or SSDs, which are used for saving data rather than transferring it. A cooling system, while essential for maintaining optimal temperatures within a computer, does not pertain to data transmission and is unrelated to the function of an external data bus. Consequently, identifying the external data bus as a physical medium for data transmission underscores its primary function in computer architecture.