The token you see in this page is your unique credential for everything API-related. If you don't know what API is, think of it this way:

When you login to ~okeanos from your web browser, you have to provide your Academic credentials. Now, once you login, what can you do? Well, virtually anything. Create VMs, destroy them, upload files to Pithos, change your password etc.

This is the natural (closer to human) way to do these things, but it's surely not the only one. If one wants to do the above in a scripted fashion, there is another communication layer where commands can be translated into VMs action etc. This is called the API ("Application Programming Interface").

A tool that uses extensively the ~okeanos API is the kamaki tool. Using it, you can do the same actions as in your browser (and more), but from your command-line. Neat, yes, but what are your credentials in this case? You got it, your token.

Every token past its expiration date is automatically updated. A manual update of a token is advised in cases when you suspect that others have managed to acquire your token.