A portable application, or portable app for short, is a software program that does not require any kind of formal installation onto a computer's permanent storage device to be executed, and can be stored on a removable storage device such as a CD-ROM, USB flash drive, flash card, or even a floppy disk, enabling it to be used on multiple computers. This does not mean that it can be taken and used on a different operating system, processing platform, or another computer with completely different hardware (i.e., those that are not compatible with the software as stated by its requirements), so it is not to be confused with the concept of software portability, which is the ability for software to be run or compiled with little modification on diverse computing platforms. Ideally it can be configured to read its configuration files from the same storage location as the software program files.