In plain words
A device is a hardware thing the computer can see and work with.
Why learners confuse it
The word device is broad, so it helps to say which device you mean instead of using it as a vague label.
A device is a piece of hardware the system can detect and use.
People often say device when they really mean one app, one cable, or the whole computer. Naming the device clearly helps troubleshooting.
A device is a hardware component or connected piece of equipment that the computer interacts with.
A device is a tool or hardware part the computer can use, like a keyboard or drive.
A device is a hardware thing the computer can see and work with.
The word device is broad, so it helps to say which device you mean instead of using it as a vague label.
Study the larger concept after the word itself becomes clear.