Which system transfers data between components inside a computer?

The data bus is the system responsible for transferring data between the various components inside a computer. It is a crucial part of the computer's architecture, as it provides a pathway for the actual data being processed to move between the CPU, memory, and peripherals. The width of the data bus, determined by the number of lines it has, influences how much data can be transferred simultaneously, impacting the overall performance of the system.

While the address bus carries information about where data should be sent, and the I/O bus manages data flow to and from input/output devices, it's the data bus that specifically serves the purpose of transferring the data itself between components. The term "communication bus" is more generic and does not specifically refer to the function of transferring data within the computer's internal architecture. Thus, the data bus is the correct choice because it uniquely fulfills the requirement of transferring data between the internal components of a computer system.