Description Abstract: Superconducting Radio Frequency (SRF) is the technology of choice for particle accelerators with high duty cycle or continuous wave operation. SRF cavities differ in shape, resonance frequency and operating field, depending on the specific requirements of each accelerator project. The superconducting material adds another dimension to the design options for an accelerator and is subject to research and development efforts in order to push the cavity performance to the ultimate limit. This presentation will discuss the current physical and technological challenges in SRF on the basis of the accelerator projects at CERN and address the R&D pathways towards future particle accelerators.