A subroutine is a sequence of programmed instructions designed to perform a specific task within a larger function. In programming for blockchain and cryptocurrency projects, subroutines streamline processes and enhance code efficiency.When developing smart contracts, subroutines allow developers to break complex functions into smaller, manageable parts. This modular approach not only makes code easier to read and maintain but also promotes reusability. For instance, if certain calculations or checks are needed in multiple places, a developer can create a subroutine once and call it wherever necessary.Subroutines can be invoked by various functions within a smart contract, saving time and reducing redundancy. They help ensure that the code runs correctly and efficiently, as errors can be isolated within smaller segments.In summary, subroutines play a key role in simplifying programming tasks, improving efficiency, and enhancing the overall quality of code in cryptocurrency applications.