It's a meaningless phrase.
LINUX and UNIX are vendor independent OS
No, it is unix-based but Linux is a kernel not an operating system.Ubuntu,Linux Mint,Debian,and puppy Linux,ect. are OS's that use the Linux kernel.
windows, mac os, unix, linux..generally all of the present versions of these OC's are multitasking ones..
what are similarities and differences between linux and unix?
No, Linux IS Unix, so the question makes no sense. Unix is a general term for a class of operating systems. Linux is also a term applied to more than one operating system variant, but all Linux OS are Unix OS. Redhat is one type of Linux. BSD is a type of Unix that is not Linux.
Mac-OS=Disk operating system==Linux OS==Windows OS==Unix OS=
Linux comes closest to mind.
Yes Mac OS is based on Linux
Dos Unix Linux Windows Mac OS OS/2
None of the above.
Yes
They are all operating system.