The origin of traveling between servers is unknown. Symbols must be carved into the portal to get to a certain server.
Servers have different rules depending on how long they’ve existed. Some servers are more different than others. Server differences are measured because people can become very ill or experience other problems or introduce something that can cause problems because of the differences.
Minigame servers like Hive, Hypixel, and Mineplex are home to competitions using command blocks to keep contestants safe. Other versions of the games exist for kids and schools.
Survival are people who choose to live in the wilderness or are attempting to start their own server.
World refers to well, the world. Server and world are used interchangeably, but servers are like countries but also the entire world. "starting a server" is like founding a town/city/country