EPS Stands for Evolved Packet System (EPS) . It is made up of EPC(Core Network ) and E-UTRAN (RAN). As shown in the figure below.
EPC High level Information
The EPC provides access to external data networks. ( e.g., internet , corporate networks etc.) and operator services.
It also performs services such as
RAN High Level Information
RAN side provides all radio related functions for active terminals meaning the terminals sending data.