Phase change materials (PCMs) offer unique properties, particularly their ability to rapidly switch between amorphous and crystalline states, which significantly alters their optical and electronic properties. This property makes PCMs attractive for photonic applications, such as all-photonic memories, color-rendering displays, and nanophotonic systems. The review discusses recent advancements in PCMs and their potential in various photonic applications. Key challenges and requirements for successful implementation are also addressed, including power consumption, switching speed, and cyclability. The article highlights the potential of PCMs in integrated optics, where they can be used to create ultra-fast, low-loss integrated optical functionalities. In thin-film applications, PCMs enable color pixels and displays with high resolution and color gamut. For nanophotonic applications, PCMs can be used in active plasmonics and metamaterials, providing reconfigurable, non-volatile functionality for manipulating and controlling light. The review concludes by discussing the future perspectives and limitations of using PCMs in emerging areas of photonics.Phase change materials (PCMs) offer unique properties, particularly their ability to rapidly switch between amorphous and crystalline states, which significantly alters their optical and electronic properties. This property makes PCMs attractive for photonic applications, such as all-photonic memories, color-rendering displays, and nanophotonic systems. The review discusses recent advancements in PCMs and their potential in various photonic applications. Key challenges and requirements for successful implementation are also addressed, including power consumption, switching speed, and cyclability. The article highlights the potential of PCMs in integrated optics, where they can be used to create ultra-fast, low-loss integrated optical functionalities. In thin-film applications, PCMs enable color pixels and displays with high resolution and color gamut. For nanophotonic applications, PCMs can be used in active plasmonics and metamaterials, providing reconfigurable, non-volatile functionality for manipulating and controlling light. The review concludes by discussing the future perspectives and limitations of using PCMs in emerging areas of photonics.