An operating system (OS) is an interface between hardware and user,
which is responsible for the management and
coordination of activities and the sharing of the resources of a
computer, that acts as a host for computing
applications run on the machine. One of the purposes of an operating
system is to handle the resource allocation and access protection of
the hardware. This relieves the application programmers from having to
manage these details.
Operating systems offer a number of services to application programs
and users. Applications access these services through application
programming interfaces (APIs) or system calls. By invoking these
interfaces, the
application can request a service from the operating system, pass
parameters, and receive the results of the operation. Users may also
interact with the operating system with some kind of software user
interface like typing commands by using command line
interface (CLI) or using a graphical user interface. For
hand-held and desktop computers, the user interface is generally
considered part of the operating system. On large systems such as
Unix-like
systems, the user interface is generally implemented as an application
program that runs outside the operating system.
While servers generally run Unix or some
Unix-like operating system, embedded system markets are split amongst
several operating systems,
although the Microsoft Windows line of operating
systems has almost 90% of the client PC market.Multi-user is a term that defines an operating system or application software that allows
concurrent access by multiple users of a computer.
Time-sharing systems are multi-user systems.
Most batch processing systems for mainframe computers may also be considered "multi-user",
to avoid leaving the CPU idle while it waits for I/O
operations to complete. However, the term "multitasking" is more common in this
context.
An example is a Unix server where multiple remote users have access
(such as via Secure Shell) to the Unix
shell prompt at the same time. Another example uses multiple X Window sessions spread across multiple terminals powered
by a single machine - this is an example of the use of thin
client.
Management systems
are implicitly designed to be used by multiple users, typically one system administrator or more and an end-user community.
The complementary term, single-user, is most commonly used
when talking about an operating system being usable only by one person
at a time, or in reference to a single-user software license agreement.
Multi-user operating systems such as Unix sometimes have a single user
state or runlevel available for emergency maintenance.
which is responsible for the management and
coordination of activities and the sharing of the resources of a
computer, that acts as a host for computing
applications run on the machine. One of the purposes of an operating
system is to handle the resource allocation and access protection of
the hardware. This relieves the application programmers from having to
manage these details.
Operating systems offer a number of services to application programs
and users. Applications access these services through application
programming interfaces (APIs) or system calls. By invoking these
interfaces, the
application can request a service from the operating system, pass
parameters, and receive the results of the operation. Users may also
interact with the operating system with some kind of software user
interface like typing commands by using command line
interface (CLI) or using a graphical user interface. For
hand-held and desktop computers, the user interface is generally
considered part of the operating system. On large systems such as
Unix-like
systems, the user interface is generally implemented as an application
program that runs outside the operating system.
While servers generally run Unix or some
Unix-like operating system, embedded system markets are split amongst
several operating systems,
although the Microsoft Windows line of operating
systems has almost 90% of the client PC market.Multi-user is a term that defines an operating system or application software that allows
concurrent access by multiple users of a computer.
Time-sharing systems are multi-user systems.
Most batch processing systems for mainframe computers may also be considered "multi-user",
to avoid leaving the CPU idle while it waits for I/O
operations to complete. However, the term "multitasking" is more common in this
context.
An example is a Unix server where multiple remote users have access
(such as via Secure Shell) to the Unix
shell prompt at the same time. Another example uses multiple X Window sessions spread across multiple terminals powered
by a single machine - this is an example of the use of thin
client.
Management systems
are implicitly designed to be used by multiple users, typically one system administrator or more and an end-user community.
The complementary term, single-user, is most commonly used
when talking about an operating system being usable only by one person
at a time, or in reference to a single-user software license agreement.
Multi-user operating systems such as Unix sometimes have a single user
state or runlevel available for emergency maintenance.