Open RAN and virtualized RAN (vRAN) can lead to the transformation of how operators and large enterprise customers procure, deploy, manage, and optimize cellular equipment. The primary focus of Open RAN and vRAN are: decoupling radio unit and baseband distributed unit and centralized unit, and decoupling hardware from software. This chapter discusses Open RAN and vRAN technologies and presents solutions for the optimized implementations. It starts by presenting the ongoing trends in the mobile network architectures. Open RAN interfaces and specifications are illustrated, and baseband centralization and virtualization are described. RAN Intelligent Controller (RIC) bring new innovations into RAN optimization. RIC provides advanced control functionality, which delivers increased efficiency and better radio resource management. O-RAN Alliance was founded in February 2018 with the intention of promoting open and intelligent RAN.