What is a portable application?

What is a portable application?

Here's what I got..Hope this would help.

(1) An application that can be converted from one computer environment to another.

(2) An application stored on a USB flash drive that can run on a computer without leaving any trace of itself when the application is finished. It is designed to restore all changed settings when the program is closed. Non-U3 portable applications are typically dependent on a particular brand of USB drive. U3 applications require U3-enabled flash drives.

Portable applications can be run on any computer system with which they are compatible but typically require a specific operating system (such as Microsoft Windows XP or above, certain version of a Linux distro, etc.)

Depending on the operating system, portability is more or less complex to implement; to operating systems such as AmigaOS, all applications are by definition portable. Portable apps are distinct from software portability where software allows its source code to be compiled for different computing platforms.