A task manager is a program

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 used to provide information about the processes

Process (computing)

In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...

 and programs running on a computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

, as well as the general status of the computer. It can also be used to terminate processes and programs, as well as change the processes priority

Priority

Priority may refer to:* Priority date, a concept of establishing waiting times in the immigration process by United States Department of State* Priority level, the priority of emergency communications...

. In some environments, users can access a task manager by pressing the buttons Control-Alt-Delete

Control-Alt-Delete

Control-Alt-Delete is a computer keyboard command on IBM PC compatible systems that can be used to reboot the computer, and summon the task manager or Windows Security in more recent versions of the Microsoft Windows operating system...

.

Task managers can display currently running services (processes) as well as those that were stopped. They can display information about the services (such as Process ID and group) if known.

Common task managers

• Windows Task Manager
  Windows Task Manager
  Windows Task Manager is a task manager application included with the Microsoft Windows NT family of operating systems that provides detailed information about computer performance and running applications, processes and CPU usage, commit charge and memory information, network activity and...
  
   on Microsoft Windows
• Activity Monitor
  Activity Monitor
  Activity Monitor is a task manager, a utility for performing different tasks to a computer processes, in the Mac OS X operating system. Some of its functions include:*Quitting or "killing" a computer process*Viewing the computer's CPU load...
  
   on Mac OS X (known as Process Viewer prior to Mac OS X v10.3
  Mac OS X v10.3
  Mac OS X Panther is the fourth major release of Mac OS X, Apple’s desktop and server operating system. It followed Mac OS X v10.2 "Jaguar" and preceded Mac OS X Tiger...
  
  )
• ps (Unix)
  Ps (Unix)
  In most Unix-like operating systems, the ps program displays the currently-running processes. A related Unix utility named top provides a real-time view of the running processes....
  
  
• top (Unix)
  Top (Unix)
  top is a program found in many Unix-like operating systems. It produces an ordered list of running processes selected by user-specified criteria, and updates it periodically. Default ordering by CPU usage, and only the top CPU consumers shown top shows how much processing power and memory are...
  
   utility present in most Unix-like systems and the archetype after which others are modeled.
• tasklist
  Tasklist
  tasklist a DOS command-line tool available in Windows, local or distant.It's the equivalent to the UNIX command ps, and can be compared with the Windows task manager , or the UNIX command top.-Usage:...
  
  
• TeamWox
• htop - available for Linux systems
• GKrellM
  GKrellM
  GKrellM is a computer program based on the GTK+ toolkit that creates a single process stack of system monitors. It can be used to monitor the status of CPUs, main memory, hard disks, network interfaces, local and remote mailboxes, and many other things. Plugins are available for a multitude of...
  
   on BSD, Linux, Solaris and Mac OS X, and Windows
• KDE System Guard
  KDE System Guard
  KDE System Guard, also known as KSysguard, is the KDE task manager and performance monitor. It can monitor both local and remote hosts. It can retrieve simple values or complex data such as tables and display this information in a variety of graphical displays. Displays can then be organized in...
  
   and KTop on KDE 3
  KDE 3
  K Desktop Environment 3 was the third series of releases of the K Desktop Environment . There were six major releases in this series.-K Desktop Environment 3.0:...
  
  .
• System Activity on KDE Software Compilation 4.
• GNOME System Monitor on GNOME
  GNOME
  GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...
  
  .
• Xfce Task Manager on XFCE
  Xfce
  Xfce is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris, and BSD – though recent compatibility issues have arisen with regard to BSD Unix platforms...
  
  .
• AIX procmon GUI process monitoring tool.