Securing traffic
Securing traffic at the network level is often a given in an on-premises network. When you create systems in a corporate network, they will usually be secure by default. In other words, anything you deploy would be inside your network and to expose it to the internet, you would need to specifically allow traffic out through a firewall.
In contrast, within Azure, many services are often public by default, and if you wanted to secure them so that they’re internal, only would you need to configure this aspect.
Important note
Many applications, even those built for internal use only, are often exposed and consumed over the internet (for example, a SaaS product). Zero trust is a common pattern that means we control access to applications via identity and conditional access policies that are applied to end devices to control access rather than firewalls.
Therefore, you may think that any form of network-level security is no longer relevant – however...