How to use this tutorial

This tutorial can be run on-line or off-line. All the files needed to run the tutorial are contained within the course. However, in order to access external links (such as the NASA home page), you need to be connected to the Internet.

This tutorial can run on a Mac, or on a PC, or on a computer running under any flavor of the UNIX operating system.

The tutorial has several lessons. Each lesson contains an explanation of the topic followed by one or more examples. Many lessons have an activity or exercise.

The best way to use this course is to do the activities in one screen (or window), while following the course in another. This can be done many ways:

Open two windows on your computer, one for the course, one for the activities.
Use two terminals (or computers), one for the course, one for the activities.
Start two terminal sessions on your terminal, one for the course, one for the activities.
Use one computer. Save your spot in the course in a bookmark, exit the browser, do the activity, then restart the browser and return to the lesson.

Now that we introduced ourselves, let's see what the Table of Contents, or index, has to offer.