What is LightDM and GDM? In Linux operating system I heard both but I don't know about them and what is called? Where they are used? Are they related to display?
LightDM is an x display manager that aims to be lightweight, fast, extensible and multi-desktop. It uses various front-ends to draw login interfaces, so-called Greeters.
Key features are:
- A well-defined greeter API allowing multiple GUIs
- Support for all display manager use cases, with plugins where appropriate
- Low code complexity
- Fast performance
LightDM offers at least the same functionality as GDM but it has a simpler code base and does not load any GNOME libraries to work. LightDM is the default display manager for Ubuntu.
LighDM configuration is governed by the configuration files in
/etc/lightdm/lightdm.conf.d/. To add your own configuration, create a new file in that directory such as
GDM (the GNOME Display Manager) is a display manager (a graphical login program) for the windowing systems X11 and Wayland.It is a highly configurable reimplementation of xdm, the X Display Manager.
Gdm allows you to log into your system with the X Window System running and supports running several different X sessions on your local machine at the same time.
The X Window System by default uses the XDM display manager. However, resolving XDM configuration issues typically involves editing a configuration file. GDM allows users to customize or troubleshoot settings without having to resort to a command line.