It depends on which server it is. Here are some: /color /summon /spin /gun /fly /stairs /moderate and more!
there are:
the possibilities for commands is endless in bedrock edition as long as you know how to add your own custom commands using command blocks which you can get by typing /give @s command_block
No. It is in WorldEdit commands.
Minecraft commands were first seen in bukkit server. We do not know when the first commands were made for bukkit servers however
Each server as its own set of commands. There is not a list of all commands available as they are different from server to server. If you want to know the commands you can use on a single player world, just use /help you the list.
the possibilities for commands is endless in bedrock edition as long as you know how to add your own custom commands using command blocks which you can get by typing /give @s command_block
no
you have to cyt
You can't have commands on minecraft classic but you can in multiplayer classic
Most likely no, because commands is only a thing that is used for computers.
/give <name> 261 1
You get a mod, such a Single Player Commands.
In multiplayer, commands are generally started with a "/" Single player commands have not yet been added, unless you get a mod that has commands, like WorldEdit. They will be added in the next update, 1.3.
't' is mostly the chat function. Type whatever you want. Many servers will have a list of commands. The only place you can get the command to show all commands, is from that specific server, they are all different.