hginit.com, revert vs update

[Mihamina Rakotomandimby]

Hi all,

Looking at: http://hginit.com/01.html
I see in the "hg revert" section:
[...]
So, when you’re working on source code with Mercurial:
     1. Make some changes
     2. See if they work
     3. If they do, commit them
     4. If they don’t, revert them
     5. GOTO 1
[...]

It's alright, I understand.
what's the difference between "revert" and "update" then?
Because I have the same behaviour if I replace "revert" with "update".

-- 
Mihamina Rakotomandimby 
Directeur de Formation et de Développement des Compétences
Mobile: +261 3456 000 19         
EMail:  m.rakotomandimby at ideoneov.com