A Linux operating system can be divided in to the following layers:
1) Hardware: This is the bottom most layer of a Linux system. It consists of monitor, CPU, memory, disks, terminals, keyboards, and other devices.
2) Linux operating system: Linux operating system runs on the hardware. It controls the hardware and manages memory, processes, file systems, and Input/Output. It also provides a system call interface for the programs.
3) System library: This is the standard library for calling specific procedures. It provides a library interface for the system calls. It has various library procedures like read, write, fork, etc.
4) Utility programs: A Linux system has several standard utility programs like compilers, shell, editors, file manipulation utilities, text processors, and other programs which can be called by the user. It provides a user interface for these programs.
5) Users: This is the topmost layer in the Linux operating system. It consists of the users of the Linux operating system.