Anotehr Basic Q. re: a circuit

Sorry for another stupid question, but, I'm looking at this
http://www.maxim-ic.com/appnotes.cfm/an_pk/1750
and can't figure out whether I can ignore, or whether I need to add in
some 
modification of something like this
http://www.instructables.com/id/S8Q5N9QFHTAIQK7/
where the first diagram says 
" PWM Dimming 0 to 3.3HZ f>15KHz 0%=shdn 100%=20mA "

A clue would be appreciated - especially since I don't know whetehr they 
mean dimming as in a Dimmer Switch on a lamp, or whether they mean 
something entirely different...

Thanks in advance -

- Kris