VPN

A Virtual Private Network (VPN) encapsulates and encrypts traffic between endpoints, creating a secure logical tunnel over an untrusted network such as the internet. Site-to-site VPNs permanently link entire networks (branch offices to headquarters) using routers or firewalls at each end, while remote-access VPNs let individual clients authenticate and connect on demand via a software client. The key exam nuance is full-tunnel versus split-tunnel: full-tunnel routes all client traffic through the gateway, maximizing security; split-tunnel sends only corporate-bound traffic through the tunnel and allows direct internet access for the rest — faster but riskier, since that traffic bypasses corporate controls.