Vulnerability
A vulnerability in IT-terms is a part of software that can possibly be exploited by hackers. Software developers and security experts continuously scan their applications and source code for possible vulnerabilities to stay ahead of breaches.
A vulnerability can also exist in the way different devices communicate with each other and the protocols that are being used for it. A vulnerability is often well-known, but not all webdevelopers are aware of them. When an unknown vulnerability has been compromised without anyone noticing, we call it a Zero-day vulnerability or Zero-day attack.
