What is a File Node?
As shown in the following diagram, the file node refers to items (such as a datasheet, a form, a dashboard, etc.) in the left-side directory of your workbench.
Please do not confuse this with the files uploaded in the attachments, as the files in the attachments are not counted as file nodes (as explained on the right side of the above picture).
How are file nodes counted?
Deleted file nodes are not included in this count.
If you create a new datasheet and a new form, it will be counted as 2 file nodes. When you delete one of them, it will decrease by one.
Here is a video to help you better understand how node counts work: