When a file or folder is deleted from Google Drive, it is not permanent deleted. Instead, it is sent to the system's trash folder. If this file or folder was deleted by accident, you may restore your content in a few simple clicks.
Restore Trashed File on Google Drive
Login to your Google account, and head to the Google Drive main interface. Then click on More > Trash.
In the right pane, right-click on the file of your choice and select Restore from trash:
Your file will be restored to your Google Drive folder.