A User-Defined Function (UDF) allows programmers to create custom functions within smart contracts or decentralized applications. This feature lets developers define specific logic tailored to their needs, enhancing the flexibility and functionality of blockchain applications.UDFs can handle various operations, such as calculations, data manipulation, or interactions between smart contracts. By using UDFs, developers can streamline processes and make their applications more efficient.Implementing UDFs can also lead to cleaner and more organized code. Instead of repeating the same code for multiple tasks, developers can write a function once and call it whenever needed. This not only saves time but also reduces the likelihood of errors.In summary, UDFs play a crucial role in enhancing the development and functionality of smart contracts, making it easier for developers to create complex applications on the blockchain.