The reset will put your desktop appearance and all settings, shortcuts, wallpapers and etc. to the factory default.
Basically, If you've gone too far with the customization of your Gnome desktop, something broke, etc., and you want to reset the Gnome desktop settings.
In this context, we shall look into how to reset Gnome Shell to its original status in Ubuntu 18.04 LTS Linux system.
How to Reset Gnome Desktop on Ubuntu 18.04 ?
To begin, Login to your Ubuntu 18.04 system and follow below steps and after that reboot your system.
Then, open the Tweaks settings on your system by searching "Tweaks" on your system. Click on Tweaks icon to launch settings.
Expand Tweaks select box at top bar of your desktop. You can see "Reset to Defaults" option, click on it.
Once you click on "Reset to Defaults" option it will prompt you for final confirmation to complete Gnome reset to its original settings.
Hit on OK button to finish and wait for few seconds to complete.
Finally, it will show success message and you will be prompted for reboot system. Hit on Restart button and it's done.