The paper provides an overview of network softwarization. This refers to network changes and adaptations regarding the convergence to Software Defined Networking and Network Function Virtualisation as well as moving the network control to Data Centers and Mobile Edge. For doing this, basic concepts and elements used in the performance provision in softwarized networking environments are used. Adequate performance frame-works can be defined, including relevant metrics and models, to be used in the development, deployment and operation of cloud and edge computing architectures as well as 5G network slicing. The paper provides an overview of network slicing, backbone of 5G technology, as well. © 2022 IEEE.