Power management keys are three keys on computer keyboard

Keyboard (computing)

In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...

s which control the 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...

's power management

Power management

Power management is a feature of some electrical appliances, especially copiers, computers and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power state when inactive. In computing this is known as PC power management and is built...

 status. They are the Power key, the Sleep key, and the Wake key:

• The Power key is used both to power on and to power off the computer.
• The Sleep key is used to put the computer to sleep, when it uses significantly lower power than when it is active, but can be woken quickly.
• The Wake key wakes the system from standby.

The power saving modes and the transition between them is usually implemented using ACPI

ACPI

ACPI may refer to:*Advanced Configuration and Power Interface for computer configuration and management*Animation Council of the Philippines, Inc....

.

On computers running Windows Vista

Windows Vista

Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

, the Windows key

Windows key

The Windows logo key—also known as the Windows key, the home key, the meta key, the start key, MOD4, or the flag key —is a keyboard key which was originally introduced on the Microsoft Natural keyboard before the release of Windows 95. This key became a standard key on PC keyboards...

 can also act as a power management key, and turns on the computer when pressed.

Keyboard layout

The placement of the three power management keys on a computer keyboard varies depending on the keyboard's model.

Ideally, these keys should be placed far enough from the rest of the keys, since the consequences of accidentally pressing one of them while using the computer (with the exception of the Wake key, which does nothing in this situation) can range from being annoying to causing data loss

Data loss

Data loss is an error condition in information systems in which information is destroyed by failures or neglect in storage, transmission, or processing. Information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data.Data loss is...

. For instance, if the user has edited a file, but not saved it yet, on some applications shutting down the system (which happens when a finger slip hits the Power key) can easily lose all the changes (although generally the more used operating systems ask the user to save the file before shut down). While the results of wrongly pressing the Sleep key aren't as extreme (unless the computer has problems returning from sleep), it can cause problems in real-time games or any application which depends on a network connection.

One common placement for these keys is in the right of the top row of the keyboard, replacing the Print Screen

Print screen

Print screen is a key present on most PC keyboards. It is typically situated in the same section as the break key and scroll lock key...

/SysRq

SysRq

System request is a key on keyboards for PCs that has no standard use. This key can be traced back to the operator interrupt key used on IBM 3270-type console keyboards of the IBM System/370 mainframe computer, which was used to cause the operating system such as VM/370 or MVS to allow the console...

, Scroll Lock

Scroll lock

Scroll lock is a keyboard button on some computer keyboards. The key is not frequently used and therefore some keyboards lack Scroll Lock altogether....

, and Pause/Break

Break key

The origins of the break key on a computer keyboard go back to telegraph practices. A standard telegraph key has a built-in knife switch that can be used to short the key's contacts. When the key was not in use, that switch was kept closed, so that a signal was continually sent...

 keys, which are moved one row down. Hereby the 2x3 block of edit and navigation keys is made to occupy the empty space just above the arrow keys

Arrow keys

Cursor movement keys or arrow keys are buttons on a computer keyboard that are either programmed or designated to move the cursor in a specified direction....

. This annoys some people, because it confuses their muscle memory

Muscle memory

Muscle memory has been used synonymously with motor learning, which is a form of procedural memory that involves consolidating a specific motor task into memory through repetition. When a movement is repeated over time, a long-term muscle memory is created for that task, eventually allowing it to...

.

Another common placement for these keys is just below the Delete

Delete key

The delete key , known less ambiguously as forward delete, performs a function when struck on a computer keyboard during text or command editing, which is to discard the character ahead of the cursor's position, moving all following characters one position "back" towards the freed letterspace. The...

, End

End key

The end key is a key commonly found on computer keyboards. The key has the opposite effect of the home key. In limited-size keyboards where the end key is missing the same functionality can be reached via the key combination of -Microsoft Windows:...

, and Page down keys, in the empty space just above the Arrow keys. When used with normal-sized keys, this can cause a high probability of accidental keypresses, especially when the typist is used to a keyboard without any keys on that position, or with the alternate arrangement described above. This leads some people to physically remove the keycap

Keycap

A keycap is a small plastic cover placed over the keyswitch of a computer keyboard. Keycaps are illustrated to indicate the key function or alphanumeric character they correspond to...

s. Some keyboard models avoid this problem by using keys with a lower height and requiring a higher force to be pressed.

Many keyboards have found a solution to this problem, in that a specific key has to be held down while the power management key is pressed. Often, this is found in the top-right of the keyboard, to the right of the lock button lights, and can be described as "opposite the escape button". With this button, the power, sleep, and wake keys don't do anything when pressed alone, and the function key does nothing, either.

Most of the original ADB

Apple Desktop Bus

Apple Desktop Bus is an obsolete bit-serial computer bus connecting low-speed devices to computers. Used primarily on the Macintosh platform, ADB equipment is still available but not supported by most Apple hardware manufactured since 1999....

 Apple Macintosh keyboards

Apple keyboard

The Apple Keyboard is a keyboard designed by Apple first for the Apple line, then the Macintosh line of computers. It is available in both wired and Bluetooth models.- Layout :...

, as well as the first USB keyboard, had a key to turn the machine on in lieu of a physical power button on the computer itself. The symbol on it was usually a triangle pointing left (◁). On most keyboards it was located at the extreme upper-right corner, above the function keys and above the right most key, or in the same vertical position and in the center. The power button was replaced with a disc eject button when the Apple Pro Keyboard was introduced, and Apple removed the ability of Macs to be switched on from the keyboard. Pressing the power button when running Mac OS brought up the shutdown dialog box, on keyboards with an eject button the combination Control-Eject is used instead (for most x-Power keyboard combinations, x-Eject is used as the replacement combination).