On a mac, when downloading things for software updates, will it take over my memory space?

Answer 1

Software Update uses some memory but I wouldn't say it "takes over". It's just like any other download which takes a lot of time and uses some processor power and some memory. How much it slows things down depends on your system. Faster processor, more RAM equals less slow-down. Some of the updates, such as Mac OS X updates, install changes to the Mac OS X which will often slow things down quite a lot.

I don't do automatic updates because I like to do the updates when I am not using the computer. Before I go to bed, I click to update. In the morning, I restart to activate what was changed.