What processor do you have (to make this simple
For more info, run a search on i586 on this site or on google.com/linux The skinny though:
i386 means that it follows "intel's" architecture, which includes AMD's cpu's
i486 is for the 486 processors
i586 is for celerons and P1 I believe
i686 is anything above that. The main thing to note is that they are backwards compatible. Meaning, if you have something better than P1, you can use things build for i386 and they will work; but not the other way around. If you have a 386, you cannot use anything about i386.