It is really simple. Every time when you are creating a new world in Minecraft, game will assign a unique number, known as a seed. This Minecraft seed keeps all information about your minecraft world which allows you to share world that you have found with others. It is important to know that any changes made to the world by player will not show in a new seed.
Seed does not keep information about your spawn place, so you will spawn in random locations of the world created by your seed.Seeds for different Minecraft versions are usually different so they will generate same world on different game versions.
How to create Minecraft Seeds?
To create a custom seed go to singleplayer world selection at the main menu and click the “Create New World” button. Then click the “More World Options” button and box will appear for you to enter Minecraft seed for the world.
Things to keep in mind
– If you want to find out seed id during the game, type “/seed” in the chat and press “Enter”.
– Minecraft versions from 1.3 – 1.5 have the same seeds.
– The Minecraft seed is case-sensitive.