Packages and updates

Installing software properly.

Package managers

Software is installed from repositories rather than downloaded from websites. apt on Debian and Ubuntu, dnf on Fedora, pacman on Arch: same idea, different spelling.

apt update refreshes the list, apt upgrade installs the new versions.
The manager handles dependencies, which is the entire reason it exists.

Trust

Piping a script from the internet straight into a shell runs unreviewed code as you. Read it first, or install from the distribution's repository.