load balance http traffic on diiferent ports

Building on David's terminology clarification, 'node' would be the back-end server IP, while 'pool member' is an ip:port combination. So you're forwarding to the same node, but different ports on the node, hence different pool members.

I tend to think of VIP as just the virtual IP address, and the combination of VIP and port/service as a 'virtual service/server'. However people use many of the terms interchangeably, hence need for clarification sometimes.

Good luck! I think you'll be in good shape.