What Does Port Scanner Mean?
A port scanner refers to a software application program that scans a server for open ports. It enables auditors and network administrators to examine network security while attackers and hackers use it to identify open ports for exploiting and/or running malicious services on a host computer or server.
Techopedia Explains Port Scanner
Port scanners work by attempting to connect to all or a set of predefined ports on a system that provides network or application access. Depending on the capabilities of the port scanner or scan requirements, a port scanner may have several operation modes including:
Although a port scanner is designed to aid network administrators in strengthening security, if used unethically by hackers it can reveal open ports that could be exploited.