Which command-line command is used for package management in Debian distributions including Ubuntu?

In Debian-based distributions such as Ubuntu, package management involves installing, updating, and removing software packages. The command used for this purpose is apt-get. This command is part of the Advanced Package Tool (APT) suite and is specifically designed to handle the .deb package files, which are the format used by Debian-based systems.

apt-get can manage packages from the official repositories and can perform several functions, including installing packages (apt-get install), updating package lists (apt-get update), and removing packages (apt-get remove). Its user-friendly interface and robust functionality make it a go-to choice for system administration in these distributions.

Other choices, while related to package management, are not directly applicable to Debian distributions. For example, .rpm refers to the Red Hat Package Manager, used by RPM-based systems such as Red Hat and Fedora. YUM (Yellowdog Updater, Modified) is a package management utility that works with RPM packages. Finally, .deb refers to the package file format itself but is not a command. Hence, apt-get stands out as the correct command for package management in Debian and Ubuntu environments.