Is modem that enables telecommuters to communicate with their office is an example of computer output?
If by "computer output" you mean data (whether documents, music
files, etc.) then the answer is No. Even if you mean is it a
computer output "device", then again the answer is No. It passes
data between computers, and since "output" involves putting
information into forms directly accessible to humans, a modem is
not an output device.