Linux Study Guide

Linux, decoded.

study guide · dual-boot on Dell Latitude 7450 · from an Ubuntu background

1 · Where the flavors come from

Unix (1969) is the ancestor. Linux is a kernel (1991) that, glued to GNU tools, became the OS. Every "distro" below is the same kernel + GNU base, dressed differently. macOS is a cousin, not a child — it descends from BSD Unix, which is why your Mac terminal feels familiar.

UNIX · 1969 BSD → macOS, FreeBSD System V commercial Unix MINIX + GNU project inspiration + userland GNU / LINUX Torvalds kernel · 1991 + GNU tools Debian Red Hat Slackware Arch Gentoo Ubuntu Mint · Pop!_OS apt / .deb most cloud + dev RHEL · Fedora Rocky · AlmaLinux dnf / .rpm Scientific Linux ✝ EOL 2024 Arch Manjaro · EndeavourOS pacman + AUR rolling release → openSUSE / SUSE (zypper)
fig. 1 — the genealogy. color = package family.
The one thing that actually changes between flavors is the package manager (apt → dnf → pacman → emerge) and release philosophy. Kernel, shell, filesystem, SSH, and 90% of commands are identical everywhere.

2 · What a Linux system is made of

Five layers, bottom to top. Coming from Ubuntu, you already know all of these — only the package layer differs by distro.

HARDWARE CPU · RAM · disk · the Dell 7450 itself KERNEL talks to hardware · drivers · memory · processes LIBRARIES (lib) shared code apps reuse · e.g. glibc SYSTEM / init starts services · systemd on most distros SHELL bash / zsh · you type here APPS browser · Claude Code · editors YOU 👤
fig. 2 — the layer cake. each layer only talks to its neighbors.
TermWhat it isSame across distros?
kernelThe core program controlling hardware, memory, processes. Literally "Linux."Yes (version varies)
shellThe command interpreter you type into (bash, zsh).Yes
system / initBoots the machine and supervises background services. Usually systemd.Mostly
libShared libraries — reusable code apps depend on (e.g. glibc).Yes
appAnything you run on top: editors, browsers, Claude Code.Yes
package mgrInstalls/updates software. apt/dnf/pacman.No — this is the main thing to relearn

3 · The filesystem — everything hangs off /

There are no drive letters. One tree starts at root /. This layout (the "FHS") is the same on every distro and even similar on macOS.

/ root of everything /bin /sbin essential commands (ls, cp) + admin tools /lib shared libraries those commands need /etc system-wide config files (text, editable) /dev devices as files — disks, ports, ttys /proc /sys virtual — live kernel + process state /usr the bulk: installed user programs + libs /var changing data — logs, caches, mail, spool /home your files: /home/john — where you live /root the admin's home (NOT the same as /) /boot the kernel + bootloader (GRUB) /tmp /opt scratch space · optional 3rd-party apps /mnt /media where USBs + other disks get mounted
fig. 3 — the Filesystem Hierarchy Standard. memorize the colored ones first.
Two you'll touch daily: /home/john (your stuff) and /etc (config). Two that confuse newcomers: /dev and /proc /sys aren't real files on disk — they're the kernel pretending to be files so you can read hardware/process state with normal tools.

4 · Choosing your distro

DistroFamilyPkg mgrDifficultyBest for / noteClaude install
UbuntuDebianapt easy What you know. Safe, huge community. 7450 is officially certified..deb
FedoraRed Hatdnf easy-mid Recommended. Teaches the RHEL/rpm half of industry; current tools..rpm
Archindependentpacman hard Build it yourself, learn deeply. Famous wiki. Rolling = always newest.AUR
Gentooindependentemerge expert Compile everything from source. Maximal control, maximal time cost.manual
RHELRed Hatdnf mid The paid enterprise standard. Learn via free Fedora/Rocky instead..rpm
Scientific LinuxRed Hatyum dead EOL June 2024. Use AlmaLinux / Rocky / CentOS Stream instead.—
beginner-friendly some learning steep / for learning's sake discontinued

YOUR QUESTIONS, ANSWERED

  • Most interchangeable across industry: Debian/Ubuntu and RHEL-family. Learn one of each.
  • Most used for remote SSH servers: Ubuntu Server, Debian, RHEL/Rocky/Alma. SSH itself is identical everywhere.
  • Best with Claude: any distro — see box at right.

CLAUDE ON LINUX

  • No official Claude Desktop for Linux (macOS + Windows only).
  • Official path = Claude Code CLI — runs on every distro, terminal-based.
  • Community repackages Desktop: .deb, .rpm, AUR, AppImage (unofficial — review the source).
Verdict for the Dell 7450: Dual-boot Fedora beside Windows 11. It stretches you into the other major ecosystem, runs current software, and stays low-friction. Keep Ubuntu in your back pocket. Try Arch later in a VM or second partition if you want the deep-dive. Skip Gentoo and Scientific Linux.

5 · Coming from Ubuntu — the cheat sheet

Almost everything transfers. The gap is the package manager.

TaskUbuntu (apt)Fedora (dnf)Arch (pacman)
Update everythingapt update && apt upgradednf upgradepacman -Syu
Install a packageapt install vimdnf install vimpacman -S vim
Remove a packageapt remove vimdnf remove vimpacman -R vim
Searchapt search vimdnf search vimpacman -Ss vim

UNCHANGED FROM UBUNTU ✓

The shell & all GNU commands · the / filesystem layout · ssh, git, vim, cron · systemd (systemctl, journalctl) · file permissions & sudo · your dotfiles in /home/john. If you can drive Ubuntu's terminal, you can drive any of them within an hour.

Dual-boot safety: back up first. In Windows, shrink the partition via Disk Management, then install Linux into the freed space — the installer's GRUB bootloader will let you pick OS at startup. Leave Windows' EFI partition alone.