Hi there and welcome
The operating system is Android, and to find out the version, go to Settings, About Device, Software Info and check the Android Version there.
That is the version you have
If you have any problems or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.