How can you list all installed packages on a Debian-based system?

To list all installed packages on a Debian-based system, using the command dpkg -l is the standard and direct approach. The dpkg command is a low-level package management tool for Debian that allows users to interact with .deb package files, and the -l option specifically instructs it to display a list of all packages installed on the system. This includes the package name, version, and a brief description of each installed package, making it a comprehensive command for package management.

In the context of the other options, while apt list --installed can also list installed packages, it operates at a higher level and relies on the APT system, so it's not as direct as using dpkg -l. The commands dpkg -i and 'list packages' do not serve the purpose of listing installed packages; dpkg -i is used for installing a package, and 'list packages' is not a valid command in a Debian-based system. Thus, the most accurate and recognized command for this purpose remains dpkg -l.