Sus chords?

[CarltonCT]

This interview was absolutely extraordinary.    I could listen to Joni talk 
all day.

http://www.jmdl.com/articles/docs/0102bc.cfm

When my own music has been written out by others, I've seen that I also use a 
lot of sus chords.  Can any of the musicians here explain exactly what a sus 
chord is?  


- Clark 

NP:  Massive Attack