Hello Mohammad
E-tree service from the point of view of the leaves looks like VPWS. From the point of view of the hub, it looks like VPLS. It doesn’t require a trunk at the hub like multiple EVCs would, but still requires leaf to leaf communication via the hub itself. Unlike multiple EVCs, it is a purely point to multipoint topology and is suitable for multicast services.
E-Tree services may or may not run over an MPLS core. RFC 7387 specifically defines the use of E-tree over an MPLS network, but as stated, it is not a requirement.
I hope this has been helpful!
Laz