I do most all of my shopping through the mail. For the holidays, I will sit down with a stack of catalogs and pore over the pages looking for possible gifts. I have a favorite catalog that has lots of interesting toys. (My nephew is two and his mother tells me he needs many new toys.) When I decide what to buy, I call an 800 number to place my order. The operator asks me some preliminary questions that require that I again go through the catalog and identify the page and the item. The next step is for me to give a credit card number. The operator now asks me how I want the item shipped. When the gift is for me, I have it shipped overnight to my work address. This insures that I get it as soon as possible and that I'll be there when it gets delivered. Since this is for my nephew, and the holidays are six weeks away, I have the gift sent to my home. The transaction is done, I finish with the operator and hang up.
The Internet has plenty of gifts. These include free software, publicly available documents (the World War II Japanese Surrender Treaty), and hundreds and hundreds of images. In order to go shopping on the Internet, I need several things:
For example, I just found out that there is a collection of Van Gogh, Monet and David images at an art archive at Harvard. Like the phone call to the mail-order catalog, I have to go to the machine at Harvard. The means of going to the collection is called ftp. The ftp process has several pieces: it takes me to the site and identifies me to the remote computer. Next, it allows me to access the collection by looking at a catalog, choose an item I want, and describe a mode for delivery. After getting what I want, I quit the remote machine and return to my own account. The ftp process delivered the image to my account on cats1. Next week, we'll discuss how I get the image from cats1 to my home machine. It's much like having to go to the UPS office, because I wasn't home when they tried to deliver my package.