The present document is an introduction to the 3GPP TS 38.47x series of technical specifications that define the F1 interface. The F1 interface provides means for interconnecting a gNB-CU and a gNB-DU of a gNB within an NG-RAN@ or for interconnecting a gNB-CU and a gNB-DU of an en-gNB within an E-UTRAN.