Operating Systems: Introduction Walkthrough | OS Basics, Kernel Space and User Space

Operating systems are something we use every day without always thinking about them. Whether it is Windows on a laptop, Linux on a server, Android on a phone, or macOS on a MacBook, the operating system is what connects users, applications, and hardware.

This TryHackMe Operating Systems: Introduction room covers the purpose of an operating system, its core responsibilities, kernel space and user space, graphical and command-line interfaces, and common OS types.

Task 1: Introduction

The scenario is straightforward: before upgrading, wiping, or repurposing an unfamiliar computer, you need to find out what you're working with.

The room introduces operating system responsibilities, common OS types, and ways to gather system information.

Answer: No answer needed. Mark the task as complete.

Task 2: The Invisible Manager

The operating system, or OS, coordinates applications and hardware. Without that coordination, programs would compete for resources without a consistent way to share them.

The room compares this to an airport: hardware provides the physical infrastructure, applications generate activity, and the OS acts as air traffic control.

Kernel Space and User Space

Modern operating systems separate privileged operations from ordinary application activity.

Kernel space: The privileged area where the kernel manages hardware and core system resources.
User space: Where regular applications run with restricted access. They request kernel services through system calls.

This separation helps prevent an application from interfering with the rest of the system.

What Does an Operating System Manage?

The main responsibilities are:

Process management: Starts, schedules, and terminates running programs.
Memory management: Allocates RAM and keeps process memory separated.
File system management: Organises files, directories, paths, and permissions.
User management: Handles accounts, authentication, and access permissions.
Device management: Uses drivers to communicate with connected hardware.

These responsibilities also form part of the system's security foundation. Authentication, permissions, and isolation are already operating before you install additional security tools.

Start the Lab Machine

To inspect the computer:

Click Start Lab Machine.
Wait for the desktop to load.
If it doesn't appear, click Show Split View.
Open the About This Computer shortcut on the desktop.

This shortcut launches System Monitor, where you can check the information needed for the next questions.

Questions and Answers

Which OS space has unrestricted access to your computer's hardware?

Answer: Kernel Space

The kernel needs privileged access to manage hardware and system resources.

Which OS responsibility manages user accounts, authentication, and permissions?

Answer: User Management

This determines who can sign in and what they can access.

What version of Ubuntu MATE is your computer running?

Answer: 1.26.2

Check the version displayed in the System tab. The value expected by the room is the MATE desktop version, rather than Ubuntu's distribution release number.

How much memory is allocated to your machine?

Answer: 1.9 GiB

In the System tab, look under Hardware for the memory value. Keep the unit as shown: GiB, not GB.

Task 3: OS Interaction and Landscape

This task looks at how we interact with operating systems and why different devices use different OS designs.

GUI vs CLI

A graphical user interface (GUI) lets you interact through windows, icons, menus, and buttons. Opening System Monitor from the desktop is a GUI interaction.

A command-line interface (CLI) lets you enter text commands. It is especially useful for automation, remote administration, and tasks that would otherwise require repeated clicking.

Both can retrieve the same information. For example, you can inspect a directory through a file manager or list its contents from a terminal.

The practical questions in this room can all be completed through the GUI.

Common Operating System Environments

Different environments have different priorities:

Desktop: Windows, macOS, and Linux support everyday work and applications.
Server: Systems such as Windows Server and Ubuntu Server support services, databases, and remote users.
Mobile: Android and iOS are designed around touch interfaces, battery life, and mobile hardware.
Embedded: Specialised systems power routers, appliances, and other dedicated devices.
Virtual and cloud: OS images run inside virtual machines and cloud instances, often with configurations suited to their workloads.

These categories overlap. Linux, for example, appears on desktops, servers, embedded devices, and cloud infrastructure.

Question 1: Identify the Filesystem

Open the File Systems tab in System Monitor. What Type is listed for the /dev/root device?

To find it:

Open About This Computer.
Select the File Systems tab.
Locate the /dev/root entry.
Read its Type column.

Answer: ext4

Ext4 is a filesystem commonly used on Linux systems.

Question 2: Count the User Directories

After opening the Home directory on the Desktop, how many user directories exist?

Open the Home shortcut and check the user directories under /home. If the shortcut opens your current user's home folder, go up one level.

Count the user folders, rather than directories such as Documents or Downloads inside an individual account.

Answer: 3

Question 3: Find the Flag in note.txt

Navigate to Alex's home directory and explore the Documents folder. What is the flag value contained in note.txt?

Follow these steps:

Open Alex's home directory.
Enter the Documents folder.
Open note.txt.
Read the flag inside the file.

Answer: THM{new_pc_for_free!}

Copy the complete flag, including the braces and exclamation mark.

Task 4: Conclusion

The final task reviews operating system responsibilities, privilege separation, and the difference between graphical and command-line interfaces.

You've also used the desktop tools to gather system information and explore a user's files.

Answer: No answer needed. Click Check to complete the room.

The suggested follow-up rooms are Windows Basics, Linux CLI Basics, and Windows CLI Basics.

Final Thoughts

This is a small investigation, but it introduces a useful habit: inspect a machine before changing it. System Monitor reveals its software version, memory allocation, and filesystem, while the file manager shows how user data is organised.

You don't need complicated tools to start understanding a computer. Knowing where to look and what each value means is the first step before moving into deeper Linux or Windows administration.

Powered by Sukshield

Follow me on

LinkedIn: Sumit Battani | Twitter: https://twitter.com/5um1t0x TryHackMe: TryHackMe | 5um1t0x

Contents