Why should many IT companies be familiar with Linux operating system in their recruitment conditions?

Because there are many background servers running Linux, you have to develop and maintain them, and you are not familiar with how to do it. Just like a soldier who is unfamiliar with the battlefield, can he still fight happily?

Linux is a Unix-like operating system, which can be used and distributed for free. It is a multi-user, multi-task, multi-thread and multi-CPU operating system based on POSIX and UNIX. It can run major UNIX tools, applications and network protocols. It supports 32-bit and 64-bit hardware. Linux inherits the network-centric design idea of Unix and is a multi-user network operating system with stable performance.

Linux operating system was born in 199 1 year1year 10/0/0/5 (this is the first official announcement time). There are many different versions of Linux, but they all use the Linux kernel. Linux can be installed on various computer hardware devices, such as mobile phones, tablets, routers, video game consoles, desktop computers, mainframes and supercomputers.

Strictly speaking, the word Linux itself only means Linux kernel, but in fact, people have become accustomed to using Linux to describe the entire operating system based on Linux kernel, and using GNU engineering tools and databases.