Azure Fundamentals AZ-900 Practice Test 3

Explanation
A network security group works like a firewall. You can attach a network security group to a virtual network and/or individual subnets within the virtual network. Youcan also attach a network security group to a network interface assigned to a virtual machine. You can use multiple network security groups within a virtual networkto restrict traffic between resources such as virtual machines and subnets
You can filter network traffic to and from Azure resources in an Azure virtual network with a network security group. A network security group contains security rulesthat allow or deny inbound network traffic to, or outbound network traffic from, several types of Azure resources
References
https://docs.microsoft.com/en-us/azure/virtual-network/security-overview