question about pear installation

Sorry to bother you,

i tried to google for the very first question for half hour, can't find my 
answer. so decided to email you, hope that it's not bothering you too much.
the question is it ask for the system-wide or local installation, if there is 
any documentation at the pear site, would you please send me the link?
or if not, would you mind that if you can give me a brief or detail description?

thanks a lot,
Chi