The Download step is triggered automatically when a web page presents something for download - this could be initiated originally by a click.
Original file path
This field is filled later and contains the source file.
Credential
If you need to save the file on a network resource you probably need a Credential to elevate the rights. Use an existing or add one.
Folder
This is the destination folder.
File mask
This is the destination file mask / file name.
Overwrite options
Control what happens if the file already exists with these settings.
Wait tab
The wait tab controls how long time the step should wait before performing the step and after performing the step (in milliseconds).