Installing Software

On Linux you don't hunt down installer executables on websites. You ask the package manager, which fetches software from curated repositories, checks it's genuine, and handles updates for everything at once. It's the app store that came before app stores — and unlike app stores, it's not a walled garden.

The main package managers

Distro family	Command	Example
Debian/Ubuntu/Mint	apt	sudo apt install htop
Fedora/RHEL	dnf	sudo dnf install htop
Arch	pacman	sudo pacman -S htop

This guide uses apt (Ubuntu/Mint/Debian/Raspberry Pi OS). The ideas are identical elsewhere; only the command name changes.

The daily workflow

sudo apt update            # refresh the LIST of available software
sudo apt upgrade           # install newer versions of what you have
sudo apt install htop      # install a package
sudo apt remove htop       # remove it (keeps its settings)
sudo apt search "editor"   # search for packages

update vs. upgrade confuses everyone: update downloads the catalog ("here's what's available now"); upgrade installs the newer versions. You almost always run update first, then upgrade. Think: check the menu, then order.

Check: sudo apt update ends with lines like Reading package lists... Done and no error lines. (It needs sudo because it writes system files.)

What "repository" means

A repository is a server full of packages that your distro's maintainers have vetted. When you apt install something, it comes from there — which is why Linux users worry less about malware than people downloading random .exe files. The trade-off: versions can lag behind the developer's website.

Beyond apt: flatpak and snap

Some apps come as flatpak or snap packages — self-contained bundles that work across distros and update independently:

flatpak install flathub org.gimp.GIMP   # example
snap install vlc                        # example

These are newer, bigger, and slightly controversial among purists. For a beginner, the practical advice is simple: use apt first; if the app you want isn't there or is ancient, try flatpak/snap.

What not to do

• Don't curl <url> | sudo bash unless you trust the source and understand the script — you're running a stranger's code as root.
• Don't add random third-party repositories (PPAs) casually. Each one is a new stranger you're trusting with system software.
• Don't download .deb files from forums when apt has the package. The repository version is vetted; the forum file is not.

Next: Remote Machines