Question 1: What is kernel?

Answer:

Kernel is a part or base of operating system. it acts as a bridge between the hardware and software.

Question 2: Is Linux an operating system or a kernel?

Answer: 

Linux is fundamentally a kernel rather than an operating system, although it constitutes a vital part of the operating system as a whole, being the most crucial component.

Question 3: Is Linux Operating System Immune to Malware?

Answer:

While Linux Operating System offers good security yet it is not immune to malware.