Instructor: Linux kernel.
Do you know there is a kernel in every Linux distribution
or Gnex distribution?
What exactly a kernel is, it actually interfaces
between your hardware and your software.
So, let's look at this diagram.
Here you will see you have at the bottom, is the hardware,
and what are those hardware?
Hardware is like CPU, memory, hard disk,
and any outside hardware, peripheral devices.
Then you have kernel.
A kernel is a program that is stored inside
of your operating system.
It's like a program, a command that keeps on running,
and what it does is it takes the commands
from shell, and shell, what is a shell?
Shell is anything like a GUI
that we have in Windows or GUI in Linux,
or if you don't have GUI in Linux,
we have terminal that runs Bash shell or C shell,
which we'll cover later on,
so when we are in that Bash or C shell terminal environment,
we execute commands,
the commands are being forwarded to kernel,
and it's kernel's responsibility to talk to the hardware
that's inside of your computer,
and then, on top of that, you have a browser, send mail,
all the application that we run, like calculator, calendar,
Office, or any Linux-related applications,
and of course, on top of that, are the users,
and that is you.
So, shell and kernel together,
that software built together in one package,
and that is called operating system,
and that operating system is any operating system
like Linux, UNIX, Mac, or Windows,
every operating system has that little program
that actually talks to your hardware,
and anything that is a shell,
which is written in C programming language as well,
that shell, or those applications are actually the software.
So this is what the word kernel means,
and we really need a kernel in any operating system
to talk to our hardware.