Selecting when and how your Goal Ends will dictate a lot about your goal, such as each Goal's Progress Bar and Checkpoints.
(1) ON: On is selected by default when you go into the "Ends" option. This simply means the goal will end on the date you select (and is the most straight forward option).
(2) IN: Selecting In gives you the option to End your goal In a specific amount of time (Example: you want the goal to end in 6 months).
(3) Choose the amount of time you want the goal to end in.
(4) EVERY: Selecting Every gives you the same time options to End your goal as "In" above, aka In a specific amount of time (Example: you want the goal to end in 1 month), but also will make the Goal Recurring. This means every time the goal ends, a new Progress Bar will be created automatically. This in essence makes the overall goal infinite, always creating a new progress bar and goal after each time selected (Example: you want to cook 8 times a month and you want that goal to always be recreated. Note: you can create checkpoints within this goal just like any other goal. So for the cooking example, the goal will end in one month, but I can create Checkpoints on a Weekly basis, that I cook at least 2 times a week. In a month's time, the goal will be recreated to Cook 8 Times in a Month, with the Weekly Checkpoints as well).
(5) Choose the amount of time you want the goal to end in. Don't forget, the goal will be recreated exactly the same, once this period ends.