So, you may still be wondering when and where to use Segmented Lists and where Master Lists are more useful.
(If you're unsure what exactly Master Lists and Segmented Lists are, please refer to the article Segmented Lists Overview for a quick primer).
A good way to think of Master Lists is as a roster. If you are continually planning events for an organization or a specific group of people, then a Master List serves as the overall list for everyone in that group. However, since it's not always reasonable to invite every single person in an organization or group to an event, you can use Segmented Lists to make subsets of this roster.
For example, if you are a volunteer coordinator for a 5th grade class, you would have a Master List that includes all of the students, parents, and classroom staff. However, for events like parent-teacher meetings, field trips, and in-school activities, you would need to have subsets of the Master List.
These subsets (Segmented Lists) might be "Students", "Students and Parents", "Teachers", "Classroom Volunteers." You can use Segmented Lists to create each of these subsets while only needing to maintain the one data source: the Master List.
However, in another case you might have data that you don't want to clutter your Master List roster with, such as lists of activities or places. In this scenario, you could add new Master Lists for each of these data sets.