Where do the updates provided by Ubuntu gets stored on the hard-disk. I see that the updates are downloaded and then installed.
It would of great help if i can get the location of the downloaded updates so that I can save the downloads to a usb or an external hard-drive because in case i need to format my system i don't need to download the updates again.
You will find the individual updates in /var/cache/apt/archives/.
When new packages are published they are added to the pool, they don't replace the older updates, so over time you'll need to prune them, or use a dedicated tool like mentioned here:
To save your updates (and all downloaded packages) you can use the aptoncd program.
