Reference:
https://buildazure.com/2016/08/18/powershell-now-open-source-and-cross-platform-linux-macos-windows/

Section: Understand Security, Privacy, Compliance and Trust
Explanation:
When you create a virtual machine, the default setting is to create a Network Security Group attached to the network interface assigned to a virtual machine.
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. You can 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 network to 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 rules that allow or deny inbound network traffic to, or outbound network traffic from, several types of Azure resources.
In this question, we need to add a rule to the network security group to allow the connection to the virtual machine on port 8080.
References:
https://docs.microsoft.com/en-us/azure/virtual-network/security-overview