If you are talking about a ban on a server, then it's however long the server owner made it.
Once you buy an Account it never expires, so forever.
Forever,
or at least until Mojang goes out of buisiness and shuts down the servers and accounts.
Forever. You pay once, play forever.
When you buy the account, it lasts forever.
You should be able tto download it as soon as you've paid for it.
There is no age limit, as long as you buy an account you have one.
Anyone can register a free Minecraft account on the Minecraft website.
Anyone can make a Minecraft account at Minecraft.net
A full minecraft account costs $26.95
You must register your account to play Minecraft, however, anyone can download Minecraft.
You can play Minecraft from as many computers as you want as long as you log in on each one from your account.
What do you mean by this? If you simply mean have minecraft on more then one computer then of course you can. As long as you have a valid account you can download minecraft onto any computer.
It's not the account that costs in Minecraft; it's the download. The cost to download Minecraft is $19.99.
You have to get an account on the real minecraft website.
It is your account that is made premium. You could log into your account from any PC that has the Minecraft client.