Marina=Protected harbour with pontoons, providing lots of individual slips for yachts.
Generally geared towards pleasure yachts.
Often incorporates a yard.
Typically camping site/parking lot atmosphere. Some like that, some hate it.
Needed if you want shore comfort style facilities for what ever reason.
Also useful if you want to leave the boat for extended periods as most provide security
of some sort.
Tends to be expensive.
Harbour=Long dock walls to moore alongside, typically geared more to commercial
ships and boats of any size.
Usually less pricey than a marina, but also with less luxurious amenities.
Boat/Shipyard=Repair facility for ships and yachts. Might be comely independent, might be part of a marina, might have a marina itself.
Needed for maintenance. Usually left once maintenance is completed.
Anchorage=Typically a protected bay where you can anchor or can take a mooring buoy.
If your boat is self sufficient you can stay there for extended periods.
A good dinghy allows you to replenish food
and get rid of trash or simply get to shore.
Sometimes used by disfortunate people living on broken and unseaworthy boats who can not afford other housing.
Liveaboard=Someone living for extended periods on a boat/yacht/ship.
Can range from living in a marina and permanently staying on one spot, rarely moving. To cruising and moving every couple of days or weeks to a new spot.
Some enjoy it one way, some the other. Everyone to its own. Just as everyone pleases.
Personally I prefer cruising and exploring new places from anchorages
Unfortunately true anchorages
get less and get more and more exploited with offering commercial
"services" which some might need, some might cherish and some might hate.
I prefer to have services not imposed on me, but to be free to choose those which I might want.
Do yachts with liveaboards need marinas? If your vessel is self sufficient and you are happy to live on anchor? Not really.
Do yachts need a ship/boat yard?
Yes, once in a long while almost everyone tends to need boatyard style facilities for maintenance for a limited period of time.