Multi-threading is a programming technique that allows a single program to perform multiple tasks simultaneously. By dividing a program into smaller threads, each thread can run independently, making better use of the computer's resources. This can lead to improved performance, especially in applications that require heavy processing or need to handle multiple tasks at once, such as web servers or video games. In a multi-threaded environment, threads share the same memory space but can execute different parts of the program concurrently. This can enhance responsiveness and efficiency, as one thread can continue working while another is waiting for input or processing data. However, managing multiple threads can also introduce complexity, such as the need for synchronization to prevent conflicts.