They are also referred to as Login Managers. As with different desktop environments, different display managers will require different system resources to run, and will provide their own unique styles, interfaces, and features. Commonly shared features - particularly in respect to the selection of display managers listed below - include customisation/theming, automatic login, and the selection of multiple desktop environments.

Plymouth configuration

If using Plymouth it is important to enable the Plymouth service specific for your chosen displaymanager

GDM

Gnome display manager

GDM - the Gnome Display Manager - is designed for use with Gnome 3. It supports theming, automatic login, and the automatic detection and use of multiple desktop environments. Specifically for those using Gnome 3. GDM is typically only paired with a Gnome Desktop Environment because GDM depends on a large amount of the Gnome desktop as dependencies.