VNC, or Virtual Network Computing, is a family of remote desktop protocols used to view and control a computer over a network. A VNC session usually sends screen updates to a client and accepts keyboard and mouse input in return, letting an administrator work on a distant system as if they were sitting in front of it.
In cybersecurity, VNC matters because remote control services are powerful entry points. If they are exposed to untrusted networks, attackers may try weak passwords, stolen credentials, or protocol flaws to gain interactive access to a host. Once inside, they can inspect files, change settings, or move deeper into the environment. Defenders reduce this risk by disabling VNC when it is not needed, restricting access with firewalls or VPNs, enforcing strong authentication, and patching any software that implements VNC-style remote administration.