git annoyances: git fetch does nothing; git pull works?

[Dan Kegel]

OK, call me a git, but
   git fetch
doesn't grab the latest changes, while
   git pull
does.  i.e. after git fetch, I can look at a file that's
listed as changed on the wine-cvs archive, and
it hasn't been updated; but after git pull, it has been.
So what good is git fetch?  Is some other command
needed to actually apply the changes that were fetched?