Emacs/Mac OS X/search and replace

[Frank Murray]

Hello,

   A new post.  I'm trying to find the feature (if Emacs, v21.2.1 on  
Mac OS X) where
you can search and replace, i.e., whatever key command, either ctrl -  
<some key>, or
Meta - <some key> in order to search for a particular character or  
string and replace it
with something else, again:

search <some text> replace with <some other text>, i.e., search "0"  
replace with "1"

Any information is appreciated.  Thanks.

fjm