from
The Free On-line Dictionary of Computing (8 July 2008)
application program
app
application software
applications software
<programming, operating system> (Or "application", "app") A
complete, self-contained program that performs a specific
function directly for the user. This is in contrast to
{system software} such as the {operating system} {kernel},
{server} processes, {libraries} which exists to support
application programs and {utility programs}.
Editors for various kinds of documents, {spreadsheets}, and
text formatters are common examples of applications. Network
applications include clients such as those for {FTP},
{electronic mail}, {telnet} and {WWW}.
The term is used fairly loosely, for instance, some might say
that a client and server together form a distributed
application, others might argue that editors and compilers
were not applications but {utility programs} for building
applications.
One distinction between an application program and the
operating system is that applications always run in {user
mode} (or "non-privileged mode"), while operating systems and
related utilities may run in {supervisor mode} (or "privileged
mode").
The term may also be used to distinguish programs which
communicate via a {graphical user interface} from those which
are executed from the {command line}.
(2007-02-02)