The stratum is a term often used in various contexts, but in the context of Biology, it refers to a layer of tissue or cells, particularly in the skin or other organs. In geology, it describes a distinct layer of sedimentary rock or soil with internally consistent characteristics. In the context of computing, particularly in blockchain technology, stratum is a communication protocol used for mining cryptocurrencies, allowing miners to efficiently share their work and receive rewards. Each usage of the term highlights the concept of layered structures or systems within its respective field.