Saving the form content means saving it to the file from which it was opened. If the form content is new, you are prompted for a filename. If the form content has been saved previously (either using Save As or Save) or has been Opened from an existing file, the form content is saved to the same file.
To save the form content:
Select Save in the toolbar
You can use [Ctrl]+[S] as a shortcut to invoke the command.
If the form content is new the Save File dialog appears. Note that depending on the configuration, the Save command may behave differently, i.e. allowing access only to the local file system.
Enter the name of the file in which to save the form content and confirm.
If the file already exists, you will be warned and asked if the new form content should overwrite the old.