Minecraft wiki entry for Classroom_Mode, associated text: Pauses game for all players: This allows an educator to pause a game completely for all users. Pausing not only prevents players from interacting but also time does not progress. This means fire does not spread, the weather does not change, mobs do not move, and so on. This is off by default.
Disables chat for all players: When enabled, this allows players in a world to communicate with each other within the world they are in via the client. This is off by default.
Perfect weather: The player can turn this switch on to disable rain. Otherwise, the players experience a usual amount of weather with occasional rain (and other weather effects). This is off by default.
Allow mobs: This is on by default. Mobs are living, moving creatures found within the Minecraft world. Friendly (creatures like chickens and ocelots) and not so friendly mobs (creatures like creepers) are allowed to appear in the world when this is turned on.
Allow destructive items: This is on by default. As an example, when enabled, players may use TNT near others. The player may also use specialty blocks (allow, deny, border) to help limit potential damage.
Players can take damage: This is on by default. This means players can take damage from the environment and mobs.
Prohibits world modification: This is off by default. The player can also use the “worldbuilder” permission to control individual building permissions within a world.
Allow players to damage each other: This is on by default. When on, players can cause damage to each other, including “friendly fire” and intentional behavior.