

s you read the following article, if there are any words or symbols you
don't understand, just place the mouse pointer over the word or symbol and the definition
will appear. (Note: The definition appears for only a few seconds; move the mouse
again and the definition will reappear.) Try this now by placing the mouse pointer
over this word: exchange
Throughout the following article on exchange, you will see buttons labeled
"Examples," like this:

Clicking on an "Examples" button will take you to a page with several
examples of the concept covered in the section of text just before the button. We
encourage you to use these "Examples" buttons frequently to clarify the concepts
and help make them real.
Apart from this, it should be fairly obvious how to use the site. If you need
help, just click on the HELP button at the top of each page.
