Three things, and everything else in Hinode is one of them.
The workspace
Your workspace is the place you come back to. It has a name you chose, an address that does not change, and a computer of its own — a small one, enough to hold a desktop, a browser and your editor open while you think.
You do not create or delete that computer. It sleeps when you stop working and wakes when you come back, and its disk is untouched in between: the applications you installed, your settings, the files in your home folder.
An account can hold more than one workspace. People use a second one to keep a client's work separate, or to keep an experiment away from something that has to keep working.
Machines
When the work needs a bigger graphics card than the workspace's own, you attach a machine. You pick two things: how much graphics memory it has, and how much system memory. Each combination has its own price per hour, and the assistant can read the current list for you rather than guess it.
A machine is a computer, not a command. It has its own name and its own address, you can open a terminal on it, install things on it, leave something running on it overnight. It starts with the same programs and settings your workspace has, so it is not a bare Linux box you have to set up again.
Machines have three states worth knowing:
- Running — it is on, and it is billing.
- Paused — you stopped it, or it put itself to sleep. What is installed on it is kept, it costs much less than running, and resuming takes a couple of minutes.
- Deleted — it is gone, and so is what was on its own disk. Anything in the shared folder is untouched, because that is not on the machine.
You can pause a machine yourself, and one that nobody is using pauses itself.
Jobs
A job is one command, run on a machine, with an outcome you can look at afterwards: what it printed, what it exited with, how long it took.
It is how you hand work to a machine and stop watching it: a training run, a long batch, anything you would otherwise sit over an SSH session for. You can ask for the machine and the job in one step; the machine stays yours afterwards, takes the next job without being rebuilt, and pauses itself when the work is done.
You are emailed when a job that ran for more than a couple of minutes ends, and jobs that end around the same time arrive as one message. You can change that to every job, only the failures, or nothing at all.
How the three fit together
The workspace is where you sit. Machines are what you add when the work is heavy. Jobs are how you hand a command to a machine without standing over it.
Nothing about that changes what you paid a moment ago: the workspace's own machine, and each machine you attached, bill separately for what they are.