The gdm package contains gdm, gdm-binary, gdmXnestchooser, gdmchooser, gdmflexiserver, gdmgreeter, gdmlogin, gdmmktemp, gdmphotosetup, gdmsetup, gdmthemetester, gdm-restart, gdm-safe-restart, gdm-stop, gdmaskpass, gdmconfig, gdmopen. gdm is a wrapper script to execute gdm-binary. gdmsetup is a graphical interface to edit the gdm.conf. gdm-restart sends the HUP signal and gdm-safe-restart sends the USR1 signal to the daemon so that it restarts. There are used after the config file is edited.