A) Openness: linux operating system abides by GNU specification, shares code, and is easy to realize system tailoring and customized development.

B) Multi-user: System resources can be accessed and used by different users with their own rights, without affecting each other.

C) Multitasking and multithreading: Different tasks and threads deal with a series of independent but internally related events almost simultaneously.

D) Device independence: linux operating system treats all external devices as device files. As long as their drivers are installed, any user can manipulate and use these devices like ordinary files without knowing their specific forms of existence.

E) Rich network functions: A perfect built-in network is a major feature of Linux. Linux is superior to other operating systems in communication and network functions. Other operating systems do not have the network connection ability closely integrated with the kernel, nor do they have the flexibility to build these network functions. Linux provides users with perfect and powerful network functions.

F) good portability

The disadvantage is that it mainly comes from the support of hardware, but for ordinary users, its operability is not as convenient and practical as windows, and ordinary users are not very good at it.