UNIX copyrighted Operating system which is used by IBM AIX, Sun Solaris and HP-UX etc., Most of the UNIX systems are commercial in nature.
Linux is considered as UNIX clone. But the traditional companies won't accept "Unix-like" but want the Unix trademark. Linux Is Just a Kernel and not the complete Operating system.
When it comes to administration, Linux is considered as most user-friendly operating systems. Unix and Linux use a different set of tools for back up of data. However, they both share some common tools such as tar, dump/restore, and cpio etc.