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The Shell

The shell is a software layer that sits between users and the operating system kernel, available as either a command-line interface or a graphical user interface (GUI). On Windows, the graphical shell is Windows Explorer, the program responsible for rendering the desktop environment, taskbar, and file navigation.

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About this video

The operating system kernel handles core system functions, but users never interact with it directly. Instead, a shell — a software layer positioned on top of the kernel — serves as the intermediary, translating user input into instructions the kernel can execute. Shells are classified into two types: command-line interfaces, which accept text-based input, and graphical user interfaces (GUIs), which present visual, point-and-click environments. On Windows 10, the GUI shell is implemented through Windows Explorer (explorer.exe), the process responsible for rendering the desktop, icons, and taskbar. Ending the Windows Explorer process through Task Manager immediately strips away the entire visual environment, leaving only the underlying system running — a clear illustration that the desktop interface is not the operating system itself, but simply a shell program running on top of it. Relaunching explorer.exe via Task Manager's Run New Task dialog restores the graphical environment instantly, confirming that the shell is a replaceable, loadable program rather than an integral part of the kernel.

What you'll learn

What's covered

The Shell

Aligned to

CompTIA Tech+
3.1 Explain the purpose of operating systems.
3.2 Compare and contrast components of an operating system.
CompTIA A+ Core 2
1.8 Explain common OS types and their purposes.
1.2 Given a scenario, use the appropriate Microsoft command-line tool.

Key terms

Shell
Software placed on top of the operating system kernel that provides an interface through which users interact with and operate the computer.
Kernel
The core component of an operating system that manages hardware resources, process scheduling, and memory, operating at the highest privilege level and separating user-facing processes from direct hardware access.
Command Line Interface
CLI
A text-based interface where users interact with an operating system or application by typing commands; it offers precise control and scriptability compared to graphical interfaces.
Graphical User Interface
GUI
A visual interface that allows users to interact with a computer or application through graphical elements such as windows, icons, buttons, and menus rather than text-only commands. Most modern operating systems use a GUI as the primary user interface.

Topics

Operating Systems Shell Command Line Interface Graphical User Interface Windows Explorer Os Kernel

Transcript

We don't interact directly with the kernel. Instead, we actually interact with the shell. The shell is software that's placed on top of the kernel, so we can interact through the shell and then operate this kernel, operate this computer.

Two types of shell

We can categorize the shell into two different types: it's either a command line, or it's a graphical user interface, or what we call a GUI.

Seeing the shell on Windows

The best way for me to explain what a shell is is just to show you. I'm on a Windows box here — this is a Windows 10 machine — and what I'm going to do is click the Windows button, or the Start button here, and type in task manager and hit enter. The other way to bring this up is just Control+Shift+Escape, and that would bring this up as well.

I'm going to scroll through here and show you that we have Windows Explorer. So here's Windows Explorer right here. That's what gives you this desktop environment right here with these different icons, and gives us the taskbar down here. So we've got all of this that's being represented through this Windows Explorer.

If I were to open up what we call a file explorer — I'm going to open up this File Explorer, and we can see File Explorer here on the top — and if I now look at Windows Explorer, it's going to show me that File Explorer is open in it. So it's part of this Windows Explorer.

Now what I'm going to do is shut this down. I'm going to right-click on this and say End task, and watch what happens: we lose that whole interface that we had. So that's the shell. We've just lost our shell.

Now, to get it back, what I can do is say File, Run new task, and I'm going to type in explorer.exe. This is the program that is the shell. So I'm going to click OK, and now I've got it back, because I've launched that program, and now I'm seeing the icons again and the taskbar. So there you go, there's the shell.

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