A keylogger is a type of surveillance software (considered to be either software or spyware) that has the capability to record every keystroke you make to a log file, usually encrypted. A keylogger recorder can record instant messages, e-mail, and any information you type at any time using your keyboard. The log file created by the keylogger can then be sent to a specified receiver. Some keylogger programs will also record any e-mail addresses you use and Web site URLs you visit.