Two statements in one post, both wrong:
The PCs in your university are basically, dumb terminals, that is, they are just images contained on a server and you are logged to a specific domain which controls your access, also known as thin clients.
In domain environment you can log in with your domain credentials from any computer which has been joined to domain. It most certainly does not have to be a dumb terminal.
This allows you to log on to any terminal on that Domain as you. It's also known as 'Single Sign On'
That's not what Single Sign On (SSO) means!
SSO is the access control system where system uses only one password, the domain password is also password for other systems and applications the user needs. Signing in to domain sends login information to other systems and applications user needs so that a single login to domain is enough, user does not have to separately login to different systems and applications he/she uses.
A typical SSO environment would be one where user logs in to domain which opens his/her Windows desktop, automatically logs the user to company intranet, and opens Office or Lotus Notes without asking users credentials.
For SSO to work all joined applications and systems have to have the same password. When password to domain expires and is changed it also has to be changed on all SSO systems and applications to match the new domain password.
More:
Single sign-on - Wikipedia, the free encyclopedia
Kari