Depends on what you are doing. soldered is for copper water lines. Threaded can be for water, gas, or anything else.
Outdoor spigots are always threaded and not soldered on.
A coupling is a threaded or soldered solid fitting, a union is a fitting that joins two pipes and can be taken apart with wrenches.
no
It is a round threaded disk shaped thing that screws into a tee or other "female" threaded fitting to " plug" it up.
When applying Teflon tape to a threaded fitting, you should wrap it in a clockwise direction.
Yes
Compression joint Soldered joint Flare joint Threaded joint
Threaded On End
Should be a threaded flared fitting
You can't. There is no fitting to do this. Galvanized has to be threaded.
A threaded copper fitting on the copper side, male or female, and the galvanized is screwed into it.
Exactly what it says threads are crossed inside the female fitting