Traditional barcodes, such as those printed on product packaging, are also known as one dimensional barcodes. There are several types commonly used, including UPC and EAN. Most look similar to this:
These 1D barcodes contain a unique code which typically describes a product, like a CD or a book. You can look this code up on the internet to find prices, reviews, and more.
If you scan a book, you can also search the contents of the book for a word or phrase, and find all the pages where it appears: