It uses both techniques.
the most popular operating system multitasking is kernel
Linux
Yes, it is multi-tasking.
The UNIX operating system is made up of three parts; the kernel, the shell and the programs.
It is a multitasking, multiuser opearting. It is a version of UNIX .
Unix
Unix is an multitasking, multi-user computer operating system developed by AT&T. It is currently owned by The Open Group. The Unix operating system was originally intended to be used for developing software.
Yes. UNIX is a computer operating system.
Yes, Unix is system software. It is a kind of operating system.
Unix came first; Linux is a clone of the Unix Operating System.
This question is beyond the capability of a short answer, which is the design of this site. In detail information is contained in any textbook on operating systems, including those that are Unix specific.