Picture pouring a bucket of water down a standard kitchen funnel. If you pour slowly, a drop at a time, the water flows smoothly through the narrow spout, but if you tip the bucket all at once, the water backs up, pools at the top, and eventually spills over the edges. For years, the Virtual Private Network (VPN) served as the corporate equivalent of that narrow funnel spout. It was designed for an era when data volume was small and entirely centralized—meaning all of a company's valuable digital assets lived inside a single, physical office server room.
A remote worker turned on their VPN, established a single encrypted tunnel back to the office firewall, and gained broad access to the local network.