What packages are installed by default in Debian? Is there a term for that set? Why some of those packages are `automatically installed` and some not?

Is there a term to refer to the subset of packages that is automatically installed by Debian distribution? I though that it had something to do with packages priorities , but it doesn't seem to be the case, cause there are packages of all the priority levels among the packages installed by default. Also, some of those packages of initial subset have automatically installed flag, e.g. wireless-tools. So they will be automatically removed if packages of the initial subset, depending on them, are manually removed. I wonder, does the installation tool keep only a list of packages to be considered manually installed and installs their dependencies automatically? **Answer to the first two questions:** After installing the core Debian utilities, Debian installer seems to invoke tasksel to carry out installation "tasks". Among the typical tasks are "standard" task and "laptop" task. From tasksel page: > "standard" task > >The standard task is a special task used by Debian Installer. It actually relies on the packages' priority. What does the "standard system" task include? > > tasksel --task-packages standard > > which is an aptitude search string that equates to > > aptitude search ~pstandard ~prequired ~pimportant -F%p So tasksel installs standard, required and important packages. > "laptop" task > > The laptop task is a special task use by Debian Installer, to pull the > packages useful on a laptop: - wireless-tools - acpi-support - cpufrequtils - acpi - wpasupplicant - powertop - acpid - apmd - pcmciautils - pm-utils - anacron - avahi-autoipd - bluetooth > Desktop See https://wiki.debian.org/DebianDesktop/Tasks