Azure Load Balancer: public vs internal, Standard SKU, backend pools, health probes, load-balancing and inbound NAT rules

Azure Load Balancer distributes incoming network traffic across a group of healthy virtual machines (VMs) or scale set instances. It works at layer 4 of the OSI (Open Systems Interconnection) model, the transport layer, so it balances TCP and UDP flows based on IP addresses and ports, without looking at HTTP content. For URL-based routing, TLS termination or a web application firewall you would use Application Gateway, a layer 7 service, instead. Load Balancer is fast, low latency and suited to any TCP or UDP protocol. A load balancer is public or internal according to its front-end IP configuration. A public load balancer has a public IP address as its front end and balances internet traffic to VMs, and it can also provide outbound internet connectivity for them. An internal load balancer has a private IP address from a subnet as its front end and balances traffic inside a virtual network (VNet) or from connected networks, for example between a web tier and an application tier.