- They can be data providers
- In that sense they have some specific characteristics, for instance they are mostly transactional and synchronous.
- They can be interfaces, for instance a Data Service will publish some data and will allow updates
A DAS for instance is able to aggregate and manipulate data through a Data Service it exposes but at the same time, the same DAS can consume other Data Services and integrate their data.
This is exactly what the Xcalia DAS is doing. It consumes and provides Data Services.