Port scanning is a technique used to identify open ports and services on a computer or network. By sending requests to various ports, a scanner can determine which ones are active and what services are running. This information helps network administrators assess security and troubleshoot issues. However, port scanning can also be used maliciously by hackers to find vulnerabilities in a system. By discovering open ports, they can exploit weaknesses to gain unauthorized access. Therefore, it's essential for organizations to monitor and secure their networks against unauthorized scanning attempts.