Which characteristic defines a Virtual Private Network (VPN)?

A Virtual Private Network (VPN) is defined primarily by its ability to allow anonymous data browsing by encrypting traffic. This encryption ensures that any data transmitted over the internet is secured and cannot be easily intercepted by third parties, which protects user privacy.

By creating a secure tunnel through which data travels, a VPN helps to mask the user's IP address and location. This feature is particularly valuable for users who wish to browse the web more privately or access content that may be restricted in their geographical area. The technology behind VPNs is centered around this capability of secure communication over potentially insecure public networks.

Other options do not represent the fundamental characteristics of VPNs. For instance, VPNs do not rely on physical cables directly connecting devices; rather, they work over any existing internet connection, which may involve various types of physical infrastructures. Furthermore, while VPNs can be configured with dedicated servers, they are not fundamentally required to be on-site; many VPNs operate through remote servers located in different regions. Finally, a key characteristic of VPNs is that they do not connect devices through public unencrypted networks in a traditional sense; instead, they create a secure, encrypted channel over those networks to ensure safety and privacy while data is in transit.