Does iCloud Backup of iOS Devices have snapshot history?
First you enable iCloud and all the services that you want to backup (for most it's all the checkboxes). During the night the iPhones makes an iCloud backup for that day.

So if you were to restore the iPhone, in setup process you could either choose to setup as new, backup from Mac or backup from the iCloud. If you choose iCloud, you would get everything back included all apps that would automatically download and network settings for example.

Here is the tricky part. While by default most people choose the iCloud backup to get their latests backup and that works for almost everyone, you can also set the iPhone as new, get back your iCloud data (contacts, messages, photos) but discard network settings and other settings that don't get included in the regular iCloud saves. When you do this on create a secondary backup that's available to choose when you will setup a new phone next time, so in a sense it's a snapshot. 
As to why you would need that, that's another questions and I for sure wouldn't rely on this method.

Here is an image of how it looks like when you have multiple iCloud backups to choose from on restore. Note also that you can delete other backups from previous phone from settings > iCloud > backups.