Definition - What does Portable Device mean?
A portable device is any device that can easily be carried. It is a small form factor of a computing device that is designed to be held and used in the hands. Portable devices are becoming an increasingly important part of personal computing as the capabilities of devices like laptops, tablets and smartphones continue to improve.
A portable device may also be called a handheld device or mobile device.
Techopedia explains Portable Device
Portable devices are primarily battery powered devices with base computing resources in the form of a processor, memory, and storage and network access. The latest portable devices are thin and lightweight, making them easy to carry and hold. This was not the case for earlier attempts at portable computers.
Small plug-and-play devices such as USB drives, external hard disks and webcams can also be called portable devices.