Difference between Sync and Backup?

I am not an expert, but it sounds to me like the back-up is a one way transfer from your device onto your computer (or other destination) while the sync updates both ways. It may also be that the back-up will store information in a different format? (not sure about that one) So, basically if you do a sync, you get the back-up included in the process

I have a question related to sync and backup option. In past several months, I kept getting "your iCloud storage is almost full" message, so I went to iPhone setting turned off "Photo Library" in "Manage Storage/Info". But after I sync/backup using iTunes (with/to both local PC and iCloud), couple of days later I found iCloud storage is almost full again. Went back to iPhone "settings/iCloud/Storage/ManageStorage/xxx'sIphoneThisiPhone/", I found under "Next Backup Size", the "Photo Library" option had been turned on again. I checked iCloud/Photos, the "iCloud Photo Library" was turned off.

Why this "Photo Library" option keeps getting turned ON after backup or sync (with local PC and/or iCloud)? How can I effectively turn off the "Photo Library" option?

"settings/iCloud/Storage/ManageStorage/xxx'sIphoneThisiPhone/", I found under "Next Backup Size", the "Photo Library" option had been turned on again. I checked iCloud/Photos, the "iCloud Photo Library" was turned off.

Why this "Photo Library" option keeps getting turned ON after backup or sync (with local PC and/or iCloud)? How can I effectively turn off the "Photo Library" option?

Your phone is doing as designed. If your iCloud Photo Library is OFF, as you say, your photos will be included in any iCloud backup.

Do you have backup enabled on your phone? If so, whenever your phone is charging, on wifi and sleeping, it backs up automatically to iCloud. This would be in ADDITION to any manual backups (tapping BACKUP NOW) you may have made.

What is it you want different from that?

LACAllen wrote:

Your phone is doing as designed. If your iCloud Photo Library is OFF, as you say, your photos will be included in any iCloud backup.

Unless you turn off backing up photos to iCloud (which I recommend) and syncing them back to your computer.

Technically, Yes but i'm not an expert on this but i did lost my other backup after i backup last week...

I have been asking this question for seven years and have never received a valid answer... and I am a network engineer.

If you review the definition in any I.T textbook, the definitions are EXACTLY the same. Sync means to transfer and verify the transfer that exact information is located in two or more places. A Backup (there are different types of backups, full, incremental, etc. - but that is not significant for this topic) is the storing of information for archival purposes at one or more locations.

THE SAME THING, and before iTunes, has always been used synonymously.

Why Apple is so elusive and fails to explain and educate (even obscure issues) it's customers effectively is a mystery in itself.

You'll get goofy answers like, "It adds 'things' to the computer and a backup saves a copy." As usual, the sentence grammatically says the same thing. No real usable information or explanation. Good luck. You'll need it.

LosAngeles wrote:

I have been asking this question for seven years and have never received a valid answer... and I am a network engineer.

Congrats on your "expertise".

Backup is one way.

Sync is two way.

So when [you] back up, the primary source is deleted over the target - for your "one-way" scenerio (because accordingly, there would not be two copies at both places - as in a "sync" process). Cool.

WHO SAYS you cant surf and drink vaseline, eh?

In Apple parlance, they are not one in the same.

Sync is a specific transfer of selected data (and by that I mean specifically selected data) from your iTunes and Photo Library to an iOS device. So, when you sync, you can sync some of your Photos, Books, Movies, TV Shows, etc. from your two libraries to your device.

Backup is storage of a particular set of selected apps and all of their associated data from your iOS device to iCloud or to iTunes. The actual apps themselves are not backed up, but rather a link to those apps is placed in the backup so that they can be automatically re-downloaded (if restoring from iCloud) or re-applied (if restoring from iTunes) when the restore is done. The Backup ensures that all data associated with those apps is restored. In addition, backups store your Settings, Messages, Ringtones, Visual Voicemail, Homescreen Layout, along with the option to back up Mail, Notes, and Documents and Data.

So, Sync goes from iTunes to iOS device, and Backup goes from iOS device to iCloud or iTunes.

You can then Restore that backup to your iOS device by erasing said device and then setting it up again from the restore. The restore places all backed up info on the device, so when the restore is complete and the apps and media are reapplied, the device looks exactly like the backup that it was restored from.

There is also iCloud syncing, which can include normal iCloud stuff like Contacts, Calendars, Notes, etc. as well as iCloud Photo Library, iCloud Music Library, and iCloud Drive. This type of sync is a two-way sync. Everything is managed by iCloud where the "source" data lives. You can update that source data at the source via iCloud.com, or you can update it via any of your devices or other computers signed into the same iCloud account with those particular features turned on. Updates from a particular device or computer go up to iCloud and then are pushed to all other devices and computers.

And you can have multiple backups stored for your device. They are backed up and distinguished by the date and timestamp. So, you can then select which one you wish to restore from. iTunes stores as many backups as your computer has room for, iCloud stores as many backups as you have iCloud space for. So, you may only have one iCloud backup for a particular device, but you can have 10 backups of that device in iTunes.

That's the difference in this world.

Cheers,

GB

I think the're the same thing : backuping something to the computer.

No - I have explained the difference just above your post. They are not the same in the world of Apple.

GB

LosAngeles wrote:

So when [you] back up, the primary source is deleted over the target - for your "one-way" scenerio (because accordingly, there would not be two copies at both places - as in a "sync" process).

What?

The primary source is your iDevice the data on this device is written to the backup folder.

The device is then sync'd with iTunes and any changes you may have made in iTunes get transferred to the iDevice and vice versa.

WHO SAYS you cant surf and drink vaseline, eh?

No idea but if you enjoy it, good for you.