Explain Like I'm Five

So operating systems are huge, they do a lot of things. They require a lot of memory and storage and some of their tasks like connecting to devices and generating images take up resources. They run a lot of programs at any given time to do all these tasks.

The kernel is a computer program but think of it as the MAIN program. It’s at the core of a computer's operating system. It’s the first program the hardware loads when you turn the computer on and it has complete control over everything in the system. It is the portion of the operating system code that is always running, always in RAM, and closing it crashes the entire computer or shuts it down. The kernel connects the hardware to the software. A full kernel controls all hardware resources (RAM, data from keyboard and mouse, data to graphics card and therefore screen), and manages all the programs running. It gives each program access to memory and the processor and even the internet. The kernel prioritizes programs and those requests.

Basically, when it is microwaved the center becomes fluffy and the corn kernal "pops" which is why we call it pop corn.

In brief, it manages the computer hardware resources. So there is the stuff to talk to the hardware and manage access to it, and the scheduler to decide which program can use the processor when.

In other words, it's a middleware for applications to talk to the hardware.

My simplest analogy for people who are knowledgeable about computers is that it's basically a giant driver.

Program wants to write to a CD? Instead of calling an obscure function in an undocumented hardware manual for every single disk ever, you let the kernel handle it by calling a well documented function that works on a lot of stuff it has drivers for.

The kernel will handle what programs want memory and will give it an address space where it can do it's thing, and will handle what CPU cycles each program gets.

An operating system is basically a kernel that is meant to run and manage programs.

I agree that this question isn't really appropriate for this forum. You can't explain how a kernel works to a 5 year old beyond extremely vague descriptions you probably already know.

If you do want to delve more into this, I'd suggest spending time on the OSDev Wiki. You could even write a toy OS for yourself. It's not as hard as it sounds.

I'm sorry but doesn't this go against this community's concept of providing simple explanations for things?

It's the main most privileged program running on a computer, through which all other programs access shared resources like hard drives, memory, network etc. It also performs access control on these resources.

I can’t explain it except when it goes bad it takes a dump and you get Blue Screen Of Death.