A security boundary is a demarcation that delineates sovereign or administrative borders that dictate who controls what. For many decades, boundaries were dictated by traditional firewalls or routers. Today’s multicloud, multiple-identity world is changing, often imaginary lines. The often global, transitory nature of many networks further erode the hardened castle walls of traditional security boundaries. The rise of virtual networks means single virtual networks spread over multiple physical sites with multiple routers and fire walls.”]
Source: https://www.csoonline.com/article/3014725/why-identity-is-the-new-security.html