Keystroke Logging

Keystroke logging (more often called keylogging or "keyloggers") is the action of tracking (or logging) the keys struck on a keyboard, typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored. It also has very legitimate uses in studies of human-computer interaction. There are numerous keylogging methods, ranging from hardware and software-based approaches to acoustic analysis.

Read more about Keystroke Logging:  History, Cracking, Countermeasures