March 2,
2012
3-28 How File Compression Works
Name: ______________________________________
http://computer.howstuffworks.com/file-compression.htm
1. What is the main purpose for zipping files(s) ?
2. List 2 programs to ZIP and unzip a compressed file.
1.
2.
3. Most types of computer files are fairly redundant -- they have the same information listed over and over
again. File-compression programs simply get rid of the_______________________________.
4. Most compression programs use a variation of the LZ adaptive dictionary-based algorithm to shrink files.
"LZ" refers to ______________ and __________, the algorithm's creators, and "dictionary" refers to the
method of cataloging pieces of data.
5. True / False
Parts of a file that uses the same (binary word or value) over and over again are
eliminated and a smaller place holders or values are assigned to that binary word that redirect
its value to one instance of that word in a file dictionary.
6. ______________ compression,t lets you recreate the original file exactly. All lossless compression is
based on the idea of breaking a file into a "smaller" form for transmission or storage and then putting it back
together on the other end so it can be used again.
7.
_____________ compression works very differently. These programs simply eliminate "unnecessary"
bits of information, tailoring the file so that it is smaller
8. ________________ compression, you can't get the original file back after it has been compressed.
9. You can't use lossy ______________ ,this sort of compression for anything that needs to be reproduced
exactly, including software applications, databases
10. What type of compression do you use if you need to reproduce a compressed file back to its original state?
Lossy OR Lossless compression
http://computer.howstuffworks.com/bittorrent.htm
1. What is BITTORRENT?
2. How is peer-to-peer file sharing different from downloading a file from a web server?
3. Define LEACHING in peer-to-peer file sharing.
4. Define tit-for-tat in bittorrent.
March 2,
2012
3-28 How File Compression Works
5. Why is peer-to-peer upload slower than peer-to-peer download when using bittorrent?
6. True / False
Bittorrnet software is open-source software.
7. Define the following Bittorrent terms.
1. SEED
2. SWARM
3. .TORRENT
4. TRACKER
8. TRUE / FALSE BitTorrent itself is perfectly legal to use
9. TRUE / FALSE BitTorrent downloads are not anonymous; information about your computer's
IP address and the files you download can be traced back to you.
10. TRUE / FALSE I have used bittorrent software in the past to download files.
11. Insert or draw a picture of how computers with bittorrent software work.
(refer to the image on http://computer.howstuffworks.com/bittorrent2.htm )