Photograph files taken with a digital camera also carry certain Exchangeable Image File Format (EXIF) data where you can see the camera settings that were set when the photo was taken.
If you are the kind of person you want to read what has been changed before updating an app you can disable the auto app update setting. Or enable if you want updates fully automated.
If you find yourself in a situation when you need to list your Mac specs or you just want know if you really got what you paid for, this is how you find them out.
If you want to make a clean install of the new OS X Mavericks or even the older versions of Mac OS X, than I strongly suggest you to create a bootable OS X key or a drive.