A VPN (virtual private network) is a protocol that creates a secure tunnel between two devices over the internet, hiding their IP addresses and encrypting their traffic. DNS (domain name system) is a protocol that translates domain names to IP addresses. IPS (intrusion prevention system) is a device that monitors and blocks malicious network traffic. SSH (secure shell) is a protocol that allows remote access and command execution on another device. Verified Reference: https://www.comptia.org/blog/what-is-a-vpn https://www.comptia.org/certifications/a