A folder in the computer's storage hierarchy that contains the executable programs users interact with. Install programs create the application folder and copy the executable files into it along with any support files that may be required. The application folder may have one or more subfolders.
Although some applications may store the data they create in the application folder, unless otherwise instructed by the user, they generally save data files in the Documents folder, the default for most operating systems. See
folder hierarchy,
install program and
Documents folder.
Windows Program Files; Mac Applications
In Windows, application folders are stored within the Program Files folder. In the Mac, they are stored within the Applications folder. Mobile devices also have a folder hierarchy, which tends to change over time. However, only techies generally get involved with most mobile folder locations, although users may look in their Download folders from time to time.
Most Users Don't Know
The overwhelming majority of users just run their programs by clicking or tapping an icon or a menu selection and have no need or desire to know where anything is stored in their devices. That is, until something goes wrong! See
Program Files,
APP file,
Finder and
Explorer.