Linux Internals !!

A Linux Operating System may it be any Distribution or Flavor include 3 main components:

1. The Kernel.
2. The Shell
3. The Application Component.

Diagrammatically this can be put as below:

The above is a very simplified diagram and does only show the very basics for your understanding and in actual there is a lot going on under which we will discuss in other posts as they come.

For now, let’s understand these layers.

1. The Linux Kernel:
   As you might have read in my earlier post how the Linux Kernel came into existence, we will now see what it actually is and what is does.
   Basically the Kernel is the Heart of the Linux Operating System. It takes the request from the user via the applications in the form of commands executed on shells and communicates the same to the hardware layer and takes the response and gives it back to the user via the same channel.
   Simple !! Isn’t it? Well yes and no, it took almost decades to make perfect the program to make it do what it does, so it actually involves a lot of code and backend processes in its operation.
   Apart from this is also does:
   1. Memory Management.
   2. Process Management
   3. CPU Management.
   4. Resource Allocation
   And so on..
   
   
2. The Shell:
   There are various shells today that we can use like the sh, csh, ksh, bash, etc. Out of all the bash is most commonly used one. It stands for “Bourne Again SHell”
   The Bash shell incorporates useful features from ksh and csh.
   Coming back to shell, a shell is basically a Command Line Interpreter, a place where a user types in a command which then interacts with the kernel and give the user their output.
   
   
3. Applications:
   The Applications are programs which we install on the operating system for doing our tasks.
   These applications communicate internally with the kernel and get the tasks done.
   These can be services, processes or daemons.
   For ex: A Web Service, A DNS Service and so on.

May it be any flavor of Linux these components stay the same, it may be modified for certain enhancements or additions, but they are there and without them the system won’t work.

Hope you liked this post, see you in another one of blog.avoidingtech.com.