You have to create a server and load the map to the server.
To install minecraft tardim time and relative dimension map on mac, you need to run their software on Mac.
Yes, it is only a custom map. All custom maps are free, and you should never have to pay to play one.
No it is a custom built map
You can make a custom map on minecraft with out a map editor by building or demolishing certain land features or you can use a seed by typing your seed in the bottom box on the "create new world" menu.
Put the new map in the minecraft_server folder then open the server.properties file and add the name or number of the map next to level-name=.
escuse me but what?
It depends on the map.
SkyBlock is a great map.
-579322790607890076 is the seed and the map is custom
the demo? you play it like you play minecraft just do what it says
to play a map, open minecraft, then click singleplayer, choose the world, then click play selected world.