ThinApp is software that allows users to create portable applications that can be run from any computer without installing them. It uses virtualization concepts to package an application and its dependencies so it is self-contained. To create a portable app with ThinApp, first select the application to package, then use ThinApp to scan the system and capture the necessary files. The captured files are then compiled into a portable format that can be run from any computer by running the executable from a USB drive or other portable storage.