Data Segmentation is more of less similar to Data Zoning itself.
Zoning is better suited when your Region or Division needs to support overlapping. For example, certain employees of your division can be part of some other divisions too. When employees who are part of multiple divisions try to access a common resource, Data Zone takes both the divisions into account and validates access accordingly.
On the other hand, Data Segment is not expected to be overlapping with one another. Say for example, Shop Locations – you can see that two shops of a retail chain are not likely to have overlapping sales.
Data Zone, Data Segments, Record Level Security, Field Level Security, Function Level Security and Component Level Security altogether make Secure First an ideal choice for secured access management.