|MadSci Network: Computer Science|
Hello, Sarah. Well, a major difference between bar codes and magnetic strips is that the information is stored in a bar code optically, as a series of rectangular black or white rectangular shapes, so you can see the bar code visually (see the bar code image below), while magnetic strips store the information magnetically, as a series of North pole-magnetized (N) and South pole magnetized (S) regions. So, you cannot see the magnetic strip's code visually.(see the magnetic stripe image at the bottom of this page). The fact that the magnetic strip's information cannot be obtained just by looking at the magnetic strip is why confidential information like your credit card number on your credit card is typically stored as a magnetic strip rather than as an optical bar code. Here is a web site that explains bar codes and how they work:
How UPC Bar Codes WorkFor magnetic strips or stripes, there are three tracks - tracks 1, 2, and 3, each of which are intended to do different things. Track 2 is generally the track that is actually used most often. Here are three web pages that explain magnetic strips and how they work: "How Stuff Works: How Does a Magnetic Stripe Work?" "Card-O-Rama: Magnetic Stripe Technology and Beyond" Magnetic Stripe Technology
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