Disabled in com.apple.periodic-daily.plist

Hi,

I have seen a lot of talk about using launchd to run the periodic jobs.
However, I could not find a comment about the Disabled flag. It seems
that in the com.apple.periodic-daily.plist the Disabled flag is true by default.

I am not sure what this actually means. Could someone explain, please?

Thanks,
  Kilian