iOS backups created with iTunes locate in
on Windows and
on Mac by default. But all filenames are unreadable like "000e2a9821065d54c80732898cf67ed8c2e86766" except four important files: "Info.plist", "Manifest.plist", "Manifest.mbdb" and "Status.plist".
Here is a list of some filenames for important iOS backup data.
There are two files related to contacts in iOS backup:
"31bb7ba8914766d4ba40d6dfb6113c8b614be442" - AddressBook.sqlitedb contains the major information of all contacts in the iOS Backup.
"cd6702cea29fe89cf280a76794405adb17f9a0ee" - AddressBookImages.slitedb contains image data for the contacts.
iPhone messages and iMessages are stored in a sqlite format database file with file name "3d0d7e5fb2ce288813306e4d4636395e047a3d28".
iPhone call history also stored in a sqlite format file, the actual file name on computer is "5a4935c78a5255723f707230a451d79c540d2741"
"12b144c0bd44f2b3dffd9186d3f9c05b917cee25" contains all photos information of the backup.
Home screen wallpaper is stored in file "b97b0c3bc8a6bb221d0849b450fbd92b5d06a301" and lock screen wallpaper file is "86736007d0166a18c646c567279b75093fc066fe".
Above are some general files for most important data. To learn more filenames, please install and run iBackup Viewer, then switch to "Raw Data" in left side navigation pane and find the expected file in file list.