Gamemodes

There are only a few different gamemodes in Minecraft (if you don't include gamemodes like Survival Games gamemodes and stuff like that), and only the PC/Mac platform can use all 4. Here are the gamemodes and what they do:

Gamemode 0 (survival): You need to mine for blocks, fight mobs, and eat food to survive. Durability of tools is existent.

Gamemode 1 (creative): No mobs will attack you. Unlimited blocks. Flight. Durability of tools is nonexistent. Instant breaking of blocks.

Gamemode 2 (adventure): You can get attacked by mobs. Not possible to break or place or harm anything.

Gamemode 3 (spectator): Invisible to Creative and Adventure and Survival players. Can go through blocks and find caves. DO NOT USE IN SURVIVAL, HIGH LEVEL CHEETING. Can see the perspectives of other players and creatures. Can still use commands and type in chat.