You should check @Danny-Miller post which does a great job in covering segment evaluation methods
https://experienceleaguecommunities.adobe.com/t5/adobe-experience-platform-blogs/peeking-underneath-...
The type of segment you choose will depend on
- the data source
- the combination of fields you have chosen in the segment ( a field from profile which is batch and a field from web which is streaming.. etc)
- The usecase you are trying to address.
I say usecase because, you could create a segment from web events which could be edge segments but may not be really required/compatible for your destination. In this case you could change the type to batch.
Until recently you did not have an option to choose the type of evaluation but this has been recently added within the UI.
Hope this helps!