1.What is kernel?
kernel is a computer operating system that is core or heart of an operating system. It is the main layer between the OS and underlying computer hardware.

2.Is Linux an operating system or a kernel?
Linux is basically a kernel, which is the core component of an operating system. The Linux kernel distributing combine various software packages ,including libraries , utilities, graphical interface to from complete operating system.

3.Is Linux Operating System Immune to Malware?
Linux systems are widely known for their security parameters. They rarely get infected by any viruses or malware. In general, it had never been seen that Linux attempted to sell anti-virus software to combat viruses. Instead, Linux is more secure than other. Linux operating systems are generally regarded as very well-protected against, but not immune to, computer viruses.