The Dell computer you are working on in Tompkins 410 is a workstation. It has its own disk drive, called C:, where programs and data can be stored; and it also provides you access to a large filesystem called T:.
Anything that happens entirely within the workstation in front of you we will call a local action. For example, if you store a file on your C: drive, we will say that you are storing it locally. Your C: drive is usually subdivided into a number of directories. Those directories can also be subdivided into subdirectories, each of which in turn can be subdivided ... Some people and machines use the names "folder" and "subfolder" for "directory" and "subdirectory". Anything in a directory or subdirectory on C: is also being stored locally. One particular directory on C: is Desktop.
One of the problems with keeping stuff on a shared workstation, such as the one you're working on in the lab, is that other users will be using that workstation while you're away from it. Some parts of the C: drive are private to you (such as your desktop), but most is available to anybody who logs in to the workstation. We cannot guarantee that next time you come to this lab you will be sitting at the same workstation. Since you want to be sure that you can get the files you create today the next time you log into a workstation, it is best to store your files on a server.
A server is just another computer, but you're usually only interested in its storage facility. When you reference the T: drive, all the machines in this lab provide access to your personal piece of the same storage facility. If today you work on a machine in the front row and store all your files on the T: drive, then next time when you work on a machine in, say, the back row, you will see all the files you saved on your T: drive. Furthermore, the T: drive actually just refers to your sharre of a very large file system. Nobody else, even if they log in to the same workstation after you log off, will have access to what you put on your T: drive.
Anything you save to the server (T: drive)
Anything you save locally to the C: drive
Using the T: drive is almost like using your own storage device and taking it with you from one workstation to another.
While you are working on a project, you may choose to work with files all of which are held locally on the computer's C: drive. This may be because you believe that it is slow and wasteful to be performing such actions over a (relatively) slow ethernet link instead of taking advantage of the fast bus speeds that data transfers entirely within your workstation can achieve.
Or you may just work with all your files stored on the T: drive. My guess is that for projects developed for this class you will not notice any degradation in performance by doing so.
Before you leave your workstation, you should make sure all the files you have been working on are on the T: drive. This is because there is absolutely no guarantee that your files will still be on the workstation the next time you log on. In fact, given the regularity with which lab machines are cleaned, there is a good chance you will lose all your careful work. If you chose to work with all your files on the T: drive, there is nothing more to do. If, however, you stored to the C: drive you will need to copy everything over to the T: drive or to your own storage device before you log out.
Next time you log on to any workstation, you can move or copy all the needed files from the T: drive to the workstation C: drive if you wish, and then commence to do all your work locally.
In a nutshell
Investigate T: now. You will see it appear under "My Computer" as drive T: You will be able to copy files to and from T: by using "cut" and "paste". Before you leave a workstation, be sure to copy any stuff you created on C: from local drives to T:. For now, let's just make a suitable spot on T: where we will keep stuff from this course. See if you can create a directory within T: called cs53. Once you have done that, see if you can create another new directory called lab1 as a subdirectory of cs53.
Later in this lab we will be looking at yet another server, on which you will be able to display your own web pages.