OK irrespective of the technology (FTTH,FTTC,FTTN,HFC,FW, Sat) the RSP (telstra, optus etc) will send you a piece of equipment. And that piece of equipment is technology agnostic. It does not matter what NBN technology you get - you get the same piece of kit from the RSP to connect to the internet
Example using Telstra: you get a "Gateway" or "Gateway Max". The only difference is that Gateway max has more ethernet ports, but essentially it is a modem/router/wireless access point/firewall.
FTTH/FW: you connect the NTD to the Gateway WAN port with an ethernet cable. The internet then comes to you as wifi or LAN ethernet ports on the Gateway. You plug in a normal analog (non ip) phone into the phone port of the Gateway.
FTTC/FTTN: you connect the phone socket to the Gateway vdsl socket with a normal phone cable - just like a normal ADSL modem. Then connect as above
HFC: you get a HFC modem (from NBN) that converts HFC signals from the NTD into ethernet signal and you connect the HFC modem to Gateway WAN port using ethernet cable just like FTTH
You could connect your computer directly to the NTD if you have FTTH/FW and the the HFC modem but them you cannot connect your normal phone and more importantly you do not have a firewall protecting your computer from malicious attacks.
NTD=network terminating device which is owned by NBN in your house. Anything you connect to NTD belongs to you. NTD to outside is NBN property. If you have ADSL/FTTN the NTD is the 1st phone socket in your house.