The Break key of a computer keyboard refers to breaking a telegraph circuit and originated with 19th century practice. In modern usage, the key has no well-defined purpose, but while this is the case, it can be used by software for miscellaneous tasks, such as to switch between multiple login sessions, to terminate a program, or to interrupt a modem connection.
Scroll Lock is a lock key on most IBM-compatible computer keyboards.
System Request is a key on personal computer keyboards that has no standard use. Introduced by IBM with the PC/AT, it was intended to be available as a special key to directly invoke low-level operating system functions with no possibility of conflicting with any existing software. A special BIOS routine – software interrupt 0x15, subfunction 0x85 – was added to signal the OS when SysRq was pushed or released. Unlike most keys, when it is pressed nothing is stored in the keyboard buffer.
A rootkit is a collection of computer software, typically malicious, designed to enable access to a computer or an area of its software that is not otherwise allowed and often masks its existence or the existence of other software. The term rootkit is a compound of "root" and the word "kit". The term "rootkit" has negative connotations through its association with malware.
A boot disk is a removable digital data storage medium from which a computer can load and run (boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting certain standards.
A backdoor is a typically covert method of bypassing normal authentication or encryption in a computer, product, embedded device, or its embodiment. Backdoors are most often used for securing remote access to a computer, or obtaining access to plaintext in cryptosystems. From there it may be used to gain access to privileged information like passwords, corrupt or delete data on hard drives, or transfer information within autoschediastic networks.
Fast user switching is a feature of a multi-user operating system which allows users to switch between user accounts without quitting applications and logging out.
Login spoofings are techniques used to steal a user's password. The user is presented with an ordinary looking login prompt for username and password, which is actually a malicious program under the control of the attacker. When the username and password are entered, this information is logged or in some way passed along to the attacker, breaching security.
The Alt keyAlt on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing A will type the letter 'a', but holding down the Alt key while pressing A will cause the computer to perform an Alt+A function, which varies from program to program. The international standard ISO/IEC 9995-2 calls it Alternate key. The key is located on either side of the space bar, but in non-US PC keyboard layouts, rather than a second Alt key, there is an 'Alt Gr' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2. With some keyboard mappings, the right Alt key can be reconfigured to function as an AltGr key although not engraved as such.
The magic SysRq key is a key combination understood by the Linux kernel, which allows the user to perform various low-level commands regardless of the system's state. It is often used to recover from freezes, or to reboot a computer without corrupting the filesystem. Its effect is similar to the computer's hardware reset button but with many more options and much more control.
In computing, Winlogon is the component of Microsoft Windows operating systems that is responsible for handling the secure attention sequence, loading the user profile on logon, and optionally locking the computer when a screensaver is running. The actual obtainment and verification of user credentials is left to other components. Winlogon is a common target for several threats that could modify its function and memory usage. Increased memory usage for this process might indicate that it has been "hijacked". In Windows Vista and later operating systems, Winlogon's roles and responsibilities have changed significantly.
In Linux systems, initrd is a scheme for loading a temporary root file system into memory, to be used as part of the Linux startup process. initrd and initramfs refer to two different methods of achieving this. Both are commonly used to make preparations before the real root file system can be mounted.
The booting process of Windows NT is the process run to start Windows NT. The process has been changed between releases, with the biggest changes being made with Windows Vista. In versions before Vista, the booting process begins when the BIOS loads the Windows NT bootloader, NTLDR. Starting with Vista, the booting process begins with either the BIOS or UEFI load the Windows Boot Manager, which replaces NTLDR as the bootloader. Next, the bootloader starts the kernel, which starts the session manager, which begins the login process. Once the user is logged in File Explorer, the graphical user interface used by Windows NT, is started.
The booting process of Microsoft Windows varies between different releases.
A computer keyboard is a peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input method for computers since the 1970s, supplemented by the computer mouse since the 1980s.
A keyboard layout is any specific physical, visual or functional arrangement of the keys, legends, or key-meaning associations (respectively) of a computer keyboard, mobile phone, or other computer-controlled typographic keyboard.
The Linux console is a system console internal to the Linux kernel. A system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. The Linux console provides a way for the kernel and other processes to send text output to the user, and to receive text input from the user. The user typically enters text with a computer keyboard and reads the output text on a computer monitor. The Linux kernel supports virtual consoles – consoles that are logically separate, but which access the same physical keyboard and display. The Linux console are implemented by the VT subsystem of the Linux kernel, and do not rely on any user space software. This is in contrast to a terminal emulator, which is a user space process that emulates a terminal, and is typically used in a graphical display environment.
In computing, rebooting is the process by which a running computer system is restarted, either intentionally or unintentionally. Reboots can be either a cold reboot in which the power to the system is physically turned off and back on again ; or a warm reboot in which the system restarts while still powered up. The term restart is used to refer to a reboot when the operating system closes all programs and finalizes all pending input and output operations before initiating a soft reboot.
Control-Alt-Delete is a computer keyboard command on IBM PC compatible computers, invoked by pressing the Delete key while holding the Control and Alt keys: Ctrl+Alt+Delete. The function of the key combination differs depending on the context but it generally interrupts or facilitates interrupting a function. For instance, in pre-boot environment or in MS-DOS, Windows 3.0 and earlier versions of Windows or OS/2, the key combination reboots the computer. Starting with Windows 95, the key combination invokes a task manager or security related component that facilitates ending a Windows session or killing a frozen application.
In computing, a status key is a keyboard key that causes an operating system and/or a program to output status information on a terminal when it is pressed. In the event that a program on a terminal produces no indications that it is running, typing the status key will reveal the program's state and activity. Older implementations produced only a quick one-line status report for the current job when the status key was pressed. Newer implementations support sending a signal to the current process to allow the application to report on status as well.
