Very often you will be confronted with compressed files. There many uses for compressed files. Let me enlighten you with some facts about zip files.
First of all a compressed file is , obviously, compressed. This means that one or more files can be present in the archive and that the total size of this file is smaller than the sum of all files sizes in the zip file.
You actually have less data on your hard drive.
This effect is created by the LWZ algorithm (the very same that is used for image compression). And as I said before, no need to know more about it (I’m just saying that because I also don’t know anything more about it :P).
When you create an archive, no matter in which form, a check mechanism is added to be able to verify if the archive is corrupt.
Suppose you download a ZIP file from the internet and halfway there the internet goes down. The ZIP file will be partially on your computer. When you open this file you’ll get the message that the archive is corrupt.
Magic? Not at all.
If you want you can also encrypt the data in your archive. Or put a password on it. (You know, for confidential pr0n and stuff like that :P).
In short how archives work… Now a word about the tools you can use to create archives.
Windows has its own compression tool. It comes with every windows installation (starting from XP).
I usually use winrar (www.rarlabs.com) but I think that the most popular tool is still Winzip (www.winzip.com). It’s used in most companies I have to go to.
A few other tools you can use are:
- Stuffit (funny :’))
Hope it helps!