Both core and RAN have user and control planes: the control plane is for configuration and management, and the user plane for carrying user data. This user data

Both core and RAN have user and control planes: the control plane is for configuration and management, and the user plane for carrying user data. This user data must go through the radio access network (RAN) and the core too. The split between core and RAN allows a single core network to manage several different access technologies. The main RAN technologies will be the 3GPP ones (LTE, NR). But it is possible to hook WiFi networks to a cellular core (there are public 3GPP specs for this), or even fixed access. The core part provides the IP access services whatever the RAN type.