Quantum resource theories (QRTs) provide a versatile framework for studying various quantum phenomena, from quantum entanglement to quantum computation. A QRT partitions quantum states into two groups: free states and resource states, with a set of free quantum operations that are restricted by natural physical constraints. The theory then explores what information processing tasks can be achieved using these restricted operations. Despite the flexibility in defining free states and operations, QRTs often exhibit surprising similarities in resource measures and convertibility, revealing deep structural connections between seemingly distinct concepts like entanglement and quantum reference frames. This article reviews the general framework of QRTs, focusing on common structural features, operational tasks, and resource measures. It highlights the benefits of framing quantum phenomena as resources, including practical applications, rigorous comparison of resource amounts, fine-grained analysis of fundamental processes, and the identification of common structures across different QRTs. The article also provides an overview of specific QRTs, such as those for entanglement, quantum reference frames, quantum thermodynamics, and quantum coherence, and discusses open problems and future research directions.Quantum resource theories (QRTs) provide a versatile framework for studying various quantum phenomena, from quantum entanglement to quantum computation. A QRT partitions quantum states into two groups: free states and resource states, with a set of free quantum operations that are restricted by natural physical constraints. The theory then explores what information processing tasks can be achieved using these restricted operations. Despite the flexibility in defining free states and operations, QRTs often exhibit surprising similarities in resource measures and convertibility, revealing deep structural connections between seemingly distinct concepts like entanglement and quantum reference frames. This article reviews the general framework of QRTs, focusing on common structural features, operational tasks, and resource measures. It highlights the benefits of framing quantum phenomena as resources, including practical applications, rigorous comparison of resource amounts, fine-grained analysis of fundamental processes, and the identification of common structures across different QRTs. The article also provides an overview of specific QRTs, such as those for entanglement, quantum reference frames, quantum thermodynamics, and quantum coherence, and discusses open problems and future research directions.