An operating system which allows
multiple programs to run at the
same time.
Multi-User
An operating system which allows
multiple users to be connected at the
same time
Single User
An operating system which
only allows a single user to
be logged on at a given
time.
Real Time
An operating system which
can react quickly enough for
an input to trigger a process
being carried out.
Distributed
An operating system where the
components are distributed across multiple
nodes. For example, word processing
software might be stored on one computer,
and spreadsheet software could be stored
on a second computer, and then data
would be stored on a third computer.