Purge trash & temporary files
Clearing out your trash and temporary files removes unwanted and unneeded files from your computer, and also frees up more space on your hard drive. You can manually empty your trash and clear your temporary files, but you can also set your computer to automatically do this for you.
Temporary files are files created automatically by applications in the background. They can increase performance by providing a copy of data that was downloaded or computed.
Automatically empty your trash and clear temporary files
Open the Activities overview and start typing Privacy.
Click on Privacy to open the panel.
Select Purge Trash & Temporary Files.
Switch one or both of the Automatically empty Trash or Automatically purge Temporary Files switches to on.
Set how often you would like your Trash and Temporary Files to be purged by changing the Purge After value.
Use the Empty Trash or Purge Temporary Files buttons to perform these actions immediately.
You can delete files immediately and permanently without using the Trash. Seefor information.