Amazon offers a lot of different services. We’re mostly going to be using Amazon EC2, which offers rental computing and hard disk space.
In Amazon vernacular, “instance” means a computer.
Amazon will happily charge you by the hour whether or not you’re using your computer. There are a couple of ways to tell them you’re not using the computer.
The first way is to terminate your instance. This deletes everything on your computer, so anything you haven’t saved goes away!
This year we’re using EBS-backed EC2 instances (acronyms!) This means that you can also shut down your computer, which preserves your configuration and other information, but discards temporary data – basically, anything under /mnt. We’ll show you some uses for this later. Note: when you shut down your computer and restart, you’re still getting charged for the information that’s being saved – it should only be about $1 / month. Terminate your computer if you don’t want this. Also note that when you shut it down and then restart it later, you will get a different computer name.
Rebooting is like powering off your laptop and powering it back on. It stops all the running programs and restarts the computer, but it doesn’t delete any information.