A VPN appliance is a network device equipped with enhanced security features. Also known as an SSL (Secure Sockets Layer) VPN appliance, it is in effect a router that provides firewall protection, load balancing, authorization, authentication and encryption for VPNs.
A VPN (virtual private network) is a network that uses a public telecommunication infrastructure such as the Internet to provide remote offices or individual users with secure access to their proprietary data. SSL is a commonly-used protocol for managing the security of message transmission on the Internet. The ideal VPN appliance offers central management and multi-platform functionality and is compatible with all essential network applications and legacy platforms.