These are all different things in networking. Hub:Where we connect all the the links for a networking connection. Node:It can be identified as a one connection. Host:is nothing than if you are going to send a request to the server the questioned system can be know as a host.
node:a port that through connect another computer or device host:host a comnputer which is in working condition/workstation hub:hub a network device that through we can connect two or more computer on a specific place it provide single broadcost domain it regenerate of signal
HUB: hub is a device that use to connect the nodes. in star topology we use HUB to provide the nodes with connection. HOST: be any end system connected to internet it may be a port-able computer, home security system, cell phone, printer etc. NOTE: host and end system be the same thing. NODE: its be the device connected to a network for example in a LAN computers and printers be nodes.
Difference between the communication and transmission. Transmission is a physical movement of information and concern issues like bit polarity, synchronisation, clock etc. Communication means the meaning full exchange of information between two communication media.