Data Entry
The 'Data Entry' section of the program is where most of the editing takes place, and you will use this screen more than any other part of the program.
The three options shown on this menu all display the same screen layout, though the data shown is 'filtered' to display only the selected subscribers.
You would mostly choose to work with 'ALL Subscribers', though if you have specific tasks that relate to current or past subscribers, then you can use those menu options to make them easier to work with.