.xinitrc
The ~/.xinitrc file is a shell script read by xinit and by its front-end startx. It is mainly used to execute desktop environments, window managers and other programs when starting the X server (e.g., starting daemons and setting environment variables).
.xprofiles
An xprofile file, ~/.xprofile and /etc/xprofile, allows you to execute commands at the beginning of the X user session - before the window manager is started.
.Xresources
Xresources is a user-level configuration dotfile, typically located at ~/.Xresources. It can be used to set X resources, which are configuration parameters for X client applications. (xrdb ~/.Xresources)
.profile
Runs on each login