It’s more efficient to open files with default application from terminal if most of your work is in terminal,so that you needn’t to open a file browser like nautilus then open the file.You need to use different file-opener based on what Desktop Environment application you are using.
Open file with Gnome’s (Unity) default application
Open file with KDE’s default application
Open file with XFCE’s default application
Open file with X’s default application
Tip:Both Gnome KDE Xfce are desktop environment which is installed on top of X Window System.So
xdg-open simply passes the arguments to that desktop environment’s file-opener application (
exo-open, respectively), which means that the associations are left up to the desktop environment.