app might imply Applicable Personal and Portable rather than only the abbreviation of APPlication For the following reasons Applicable yeah app could not be system utilities only provided for purpose of application Personal app could not be copied onto other s computer or even another partition of this same HDD tricks are exceptions Portable no matter Windows 8 or Windows RT no matter IA 32 x86 64 or ARM might potentially share the same app without worries OK that is only my guess