Which method is used to enumerate vulnerabilities, services, and applications?

Port evasion refers to techniques used to bypass port-based security controls, not to enumerate services or vulnerabilities.

Encryption is a method of securing data confidentiality and integrity, not a technique for discovering services or vulnerabilities.

DNS tunneling is a technique used for data exfiltration or command and control over DNS, not for initial enumeration of services or vulnerabilities.

Port scanning is a reconnaissance technique used to identify open ports on a network, which indicates active services and applications running on a system. This enumeration process is a crucial step for both attackers and security professionals to discover potential vulnerabilities.