External Data Bus vs. Internal Data Bus

Well, after procrastinating for forever, I'm going through an A+ study guide. However, there seems to be a possible error and I just wanted to clarify things. In the guide, it says the External Data Bus allows the processor to communicate with the computer. When an external wire connecting to the processor receives voltage, the internal wire inside the processor receives voltage. But I thought that was the Internal Data Bus. Doesn't the External Data Bus process information to and from external PC components such as USB devices? Which bus processes data for internal devices, such as expansion cards and RAM? Could someone please explain the difference between an EDB and IDB? Thanks for any info :)

I've never heard either of those terms. But a "bus" is just a group of wires to move data around. So if you're talking relative to the cpu, an "internal" bus exists within the CPU, and an "external" bus is outside of the CPU.