Session 1 · Week 1 · Handout A
The layers of a computer
Name

Date
Every piece of hardware or software belongs to one of four layers: Hardware, Firmware, Operating System, or Application. Some items may belong to more than one layer — if so, mark them in both and explain why in the last column. There are no trick questions, but there are items that are genuinely in between.
Items to classify
1. The Chrome browser
9. RAM (memory)
2. The CPU (processor)
10. Konsole (terminal emulator)
3. The Wi-Fi driver
11. An NVIDIA GPU
4. The keyboard
12. Bash (the shell)
5. LibreOffice Writer
13. A video file stored on disk
6. The Linux kernel
14. systemd (startup manager)
7. An HDMI port
15. The laptop screen
8. The desktop wallpaper image
Classification table
# Item Layer(s) Why / notes
1Chrome browser
2CPU
3Wi-Fi driver
4Keyboard
5LibreOffice Writer
6Linux kernel
7HDMI port
8Wallpaper image
9RAM
10Konsole (terminal)
11NVIDIA GPU
12Bash (shell)
13Video file on disk
14systemd
15Laptop screen
Items that belong to more than one layer — explain the boundary
Item:
Because:
Item:
Because:
Item:
Because:
When you press the power button, describe what happens layer by layer — from hardware to the desktop appearing on screen. Use the back of this sheet.
Session 7 · Week 2 · Handout B
Paths — reading and writing addresses
Name

Date
Use the filesystem map below to answer the path tasks. Write your answers first, then verify them on the actual machine using cd and pwd. Tick the verify box when you have confirmed each answer.
Filesystem map
/
├── home/
│   ├── anna/
│   │   ├── documents/
│   │   │   ├── essay.txt
│   │   │   └── notes/
│   │   │        └── readme.txt
│   │   ├── pictures/
│   │   │   └── photo.jpg
│   │   └── scripts/
│   │        └── backup.sh
│   └── carlos/
│        ├── documents/
│        │   └── report.txt
│        └── music/
├── etc/
│   ├── hostname
│   ├── passwd
│   └── apt/
│        └── sources.list
├── var/
│   └── log/
│        └── syslog
├── usr/
│   └── bin/
│        └── bash
└── tmp/
     └── tempfile.txt
Path tasks
1. Write the absolute path from / to anna's readme.txt file.
Your answer
verified on terminal
2. You are currently in /home/anna/documents. Write a relative path to reach /home/anna/pictures.
Your answer
verified on terminal
3. You are currently in /etc. Write a relative path to reach /var/log.
Your answer
verified on terminal
4. Write the absolute path to the bash executable.
Your answer
verified on terminal
5. You are in /usr/bin. Write a relative path to reach the root directory /.
Your answer
verified on terminal
6. You are in /usr/bin. What directory do you end up in after running cd ../../home/anna? Predict first, then verify.
Your prediction
What pwd shows after running it
prediction was correct
Remember: ~ always means your home directory. . means current directory. .. means one level up.
Session 11 · Week 3 · Handout C
File permissions — reading the permission string
Name

Date
First character — file type
- regular file
d directory
l symbolic link (shortcut)
Permission characters
r read — can see contents / list directory
w write — can modify / create files inside
x execute — can run as program / enter directory
- permission not set
Structure of the full string
  -   r w x   r - x   r - -
  type   owner    group    others
Decode each permission string
# Permission string File or directory? What can the owner do? What can the group do? What can others do?
1 drwxr-xr-x
2 -rw-r--r--
3 -rwx------
4 drwx--x--x
5 -rw-rw-r--
6 lrwxrwxrwx
7 ----------
8 drwxrwxrwx
Think carefully — item 4 and item 8
Item 4drwx--x--x: group and others have execute but NOT read on this directory. What does that actually mean they can and cannot do? Why would anyone set permissions this way?
Item 8drwxrwxrwx: everyone has full access to this directory. Why is this almost always a mistake? Give a specific real-world example of what could go wrong.
755 =
644 =
600 =
700 =
Session 16 · Week 4 · Handout D
Phase 1 vocabulary checklist
Name

Date
For each term, tick the green box if you can explain it clearly in your own words without looking it up. Tick the red box if you need to review it. Be honest — this is for you, not for a grade.
I can explain this clearly
I need to review this
Week 1 — the operating system
hardware
firmware / BIOS
kernel
operating system
application
abstraction
open source
GPL licence
source code
distro
desktop environment
LTS
package manager
rolling release
bootloader / GRUB
Week 2 — the filesystem
/ (root directory)
filesystem tree
mount point
pwd
ls / ls -la
cd
~ (home shortcut)
/home
/etc
/var / /var/log
/usr / /usr/bin
/tmp
absolute path
relative path
. and ..
hidden file / dotfile
.bashrc
case-sensitive
Week 3 — users and permissions
user
UID
GID
group
whoami
id (command)
root (user)
UID 0
sudo
privilege
permission string
r / w / x
owner / group / others
chmod
chmod +x
755 / 644 / 600
least privilege
/etc/shadow
Week 4 — terminal and recovery
mkdir -p
touch
echo >
rm (no undo)
permission denied
stderr
exit code
man (command)
man -k
SYNOPSIS
flag / option
sudo apt install
1. Which concept took the longest to understand? What finally made it click?
2. Which concept surprised you most? Why?
3. Complete this sentence: "A Linux filesystem is different from Windows because ___"
4. In one sentence: why does Linux have a permission system at all?