I thought Steam(trains) was finish around 1979, now we have to put up with it, to update GG. How actually does the "Verify Integrity of application cache" actually work ?. Stated yesterday after Verification I had 13 files that needed updating, then actually downloaded 1 file only. I waited for more files, did another Verification and Steam stated I had 5 files to download, after no success I Verified again, and Steam stated I had 15 files to download.

When does Steam actually go into download mode ?.

I like to shutdown my internet link when I don't need access to the web, I believe that gives hackers less time to mess with my computer. Why should I be forced to have the Internet on all of the time to receive my GG updates.

Never wanted to be on Steam at all.

The verify cache checks the files on your hard drive and compares each one to the version Steam has on its servers, if a difference is found it will download the missing files and fix. Sometimes it can find multiple files that need fixing but it will only download one, this is because the files are stored grouped in the compressed archives on the server and downloaded one files extracts to replace multiple.

If you find yourself having to verify and download a lot it usually means you have an unstable internet connection and files get corrupted in transit. Either that or you have a faulty drive.

As for shutting down your internet to avoid hackers, this will have almost no impact if you are running an up to date firewall (which comes with Windows as standard), you are actually putting yourself at risk more by not immediately getting software patches and then going online at a later date without the latest patches. Hackers normally gain access to a system via an application installed on your system (viruses) not by attempting to find vulnerabilities in your network, hacking a network is much harder. You can limit risk of hacking while having always on internet simply by having anti-virus and a firewall with default settings.

I agree with The next

It's not posible to get hacked by just being on the Internet unless someone on the same Wifi as you sets for it However if you go download a lot of shady files online that seems the most likely for you to get a virus or trojan.

As for Steam i can understand a bit the online thing however it's nice to have one place with all your game collection and should your computer or psysical games get stolen you will always have access to them