A keystroke logger (or keylogger for short) is a term often used in computer world to describe software that records every single press of a keyboard or mouse. A key logging software is spy software that runs invisibly in the background on someone’s computer.
Keystroke loggers can be hardware based or software based. Nowadays, it’s mostly software based as hardware requires time to install on someone’s computer. Software is digital, which means that it can be installed remotely via internet. Hackers sometimes create their own versions of keystroke loggers to infect computers and snatch the vital data. Things like passwords, login names, bank account numbers, safe lock codes and so on…
One way to defend your personal/business computers from keystroke loggers is to use antivirus, firewall software to stop illegal breach. However, sophisticated hackers already know ways around that so it is very possible that you’ll never know if your moves are being recorded or not.