Minecraft wiki entry for Commands, associated text: Some commands have restrictions on who can use the command or in what context.
None: The command has no restriction.
Cheat only‌[Bedrock Edition only]: When executed by a player, the command is available only if cheats is enabled.
In Bedrock Edition, when cheats is disabled, these commands can't be used by players even if they have a high permission level. In Java Edition, if players have a high enough permission level, they can use corresponding commands regardless of whether cheats are allowed.
Dedicated server only: The command is available only on a dedicated server.
No command blocks: The command cannot be executed by a command block. This is true if the permission level is higher than 2 in In Java Edition and higher than 1 in In Bedrock Edition