Is operating system Universal Turing Machine?

Question

The definition of UTM(Universal Turing Machine) is a Turing machine that can simulate other Turing machines, so as far as I can guess operating system is a UTM, since it can run multiple programs on a OS.

Answer 1

An operating system is just a software framework. You don't need an operating system to run multiple programs; software programs can run quite happily without it. You need an operating system because of the services that it provides.

Change your question to ask about any other service-oriented framework, and it still makes sense (even though the answer is still no).

The definition of UTM(Universal Turing Machine) is a Turing machine that can simulate other Turing machines, so as far as I can guess Angular 2 is a UTM, since it can run multiple programs on Angular 2.

Where you're getting hung up here is on the word simulation. An OS does not simulate a Turing machine in order to run your programs. That is not its purpose.