Keylogger is a malicious computer program that records everything you type on the keyboard and learns the keystroke pattern including words, characters, symbols and sends all the recorded details to the malicious hackers.

But technically, keyloggers are software. There has been a misconception that keyloggers are always used for criminal purpose. In reality, keyloggers have professional and legal usage also.

Imagine an invisible camera kept above your keyboard which records everything you type and sends it to the person who kept it. These are called keyloggers.