A question for the computer gurus!

That's a Mac/Apple for you. Personally I don't understand it either. I'd rather put up with the constant security threat than restarting a machine for a simple software update.

 

Err, sorry, no it's not! - The reboot requirement is at least, if not more, prevalent in PC land. In fact, PC's tend to "hedge their bets" with a "reboot may be required" message. At least Apple updates tell you ahead of time if a reboot will be required after installation.

Even the mighty Linux will often tell you to reboot after a "major" install.

The short answer is it's a lot easier for the S/W writers if they can "assume" a clean system, and that's only possible at boot time. [For the purists, yes, it is generally possible to code around it but it's a LOT of extra work and can open a can of worms that was never envisaged.]

The longer answer to the question however requires an understanding of what happens when a system (of whatever flavor) starts up - Taking your iTunes example it has processes running in the background all the time. The installation process knows this and rather than modifying the running code (typically a dangerous scenario) the install "prepares" the new version. Upon reboot, the old is "ignored" and the new gets loaded. It's simply safer and more reliable on a "desktop" class machine which the user is used to restarting every day. [Or, in the case of most PC's, which crashes every day ]

An oversimplification without getting into DLL's and the registry (on PC's), plists (on Mac's) and kexts (etc!) on Linux, but suffice to say it's "safer" that way.....

Cheers,
Ian

 

Hate to attack this like the uber-Apple fanboy I am, but you're asking for trouble

Atleast my if my MacBook needs to restart, it'll be back in working condition in less than a minute.