Keystroke logging, often referred to as keylogging or keyboard capturing, is the action of recording (logging) the keys struck on a keyboard, typically covertly, so that a person using the keyboard is unaware that their actions are being monitored. Data can then be retrieved by the person operating the logging program. A keystroke recorder or keylogger can be either software or hardware.
A logfile from a software-based keylogger, based on the screen capture above
A hardware-based keylogger
A connected hardware-based keylogger
The technology of computer keyboards includes many elements. Many different keyboard technologies have been developed for consumer demands and optimized for industrial applications. The standard full-size (100%) computer alphanumeric keyboard typically uses 101 to 105 keys; keyboards integrated in laptop computers are typically less comprehensive.
Keyboard construction of a typical notebook computer keyboard, in four layers.
A typical membrane assembly
Atari 400 keyboard
Most keyboards are rigid, but this keyboard is flexible.