As its name, you can obtain a command block through commands. Make sense, right? There are 2 commands you can type in the chat (press T or Enter) to get a command block: /give @s minecraft:command ...

Command Blocks are extremely useful for Minecraft players who want to create adventure maps and host servers.

Even if the player tried to, creating a perfect circle using normal blocks is impossible. However, there is a way of creating a perfect circle with the help of commands.

Minecraft players can turn off mobs in their server settings, using commands, or they can even turn off individual monsters using Command Blocks.