This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
I guess you're asking what the difference is between URI and URL?
The Bunkhouse Porch forum of the Javaranch is for discussions about books. I'm going to move your post to a different forum where your question is more likely to get answered. How about Java in General - Beginner...
A tip for the future: you'll help yourself a lot by giving your post a subject that is a little more specific than "computer". No reason to be shy around here, go ahead and get wordy