Exactly - stacks of updates from the first day of the OS's release.
The older the OS the more updates that are needed to get your system up to seed.
Deleting the available i OS update from the device will stop the update reminder from appearing, but you have to disconnect from wi-fi and avoid wireless networks because the moment your device is unattended and back on wi-fi…
the i OS update will download itself again and start pestering you again.
When you see the i OS Software Update reminder, choose “Later” and then choose “Remind Me Later” – don’t worry, it will remind you later. The best way to stop being nagged about impending i OS updates available is to delete the i OS update from the i Phone, i Pad, or i Pod touch, and then avoid wi-fi.
Or you may switch between versions of your files for experimental features.
The process of creating different versions (snapshots) in the repository is depicted in the following graphic.
Of course each of these systems required an additional time investment to get them updated, squared away and ready for use.
Between the checking, downloading and installation of the updates they took a significant amount of time before they were 100% up to date.
Please note that this picture fits primarily to Git.