Used in computing contexts to describe software or devices that can be carried and used on different systems without installation.
This application is portable, so you can carry it on a USB flash drive.
ポータブル is a more general term for portable devices or software, while 携帯可能 is a technical term often used in computing specifications.
Compound of 携帯 (keitai, 'carrying') and 可能 (kanō, 'possible').