What is NSG's?

NSGs, or Network Security Groups, are a fundamental security feature in Microsoft Azure. They act as a virtual firewall for your Azure resources, controlling inbound and outbound network traffic. NSGs contain security rules that allow or deny network traffic to and from several types of Azure resources. You can associate NSGs with subnets within an Azure Virtual Network (VNet), network interfaces (NICs) attached to VMs, or both. By creating and configuring NSG rules, you can define granular network access policies, protecting your applications and data from unauthorized access, such as blocking specific ports, IP addresses, or protocols.