Why Linux is virus free operating system?

Linux malware includes viruses, Trojans, worms and other types of malware that affect the Linux operating system. Linux, Unix and other Unix-like computer operating systems are generally regarded as very well-protected against, but not immune to, computer viruses.

How is Linux protected from virus?

Linux has a reputation for being a safe platform. Its permission-based structure, in which regular users are automatically prevented from performing administrative actions, predated many advances in Windows security.