Why do some applications require an admin password to install and some don't?

Why is it that some applications require me to type in my admin password for them to install, while other applications don't?
ie: Microsoft Office 2008 and Adobe CS3 require an admin password.
While the majority of other apps don't require it at all.

I think it has something to do with root access, but why would an application even need root access, while others don't?




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You only have access privileges to some directories on your machine. For ones that you don't, you have to give a password that has administrator privileges so you can write files to those directories. In the case of the examples you gave, Office and CS3 would presumably write files to directories that you don't have privilege to otherwise.

Not with root access. Some programs install stuff into the system folders. Any change made to the system will require your password.

van beat me to it, takes longer for us old timers to type stuff in