A multithreaded application is a program that can perform multiple tasks simultaneously by using multiple threads. A thread is a smaller unit of a process that can run independently, allowing the application to execute different parts of its code at the same time. This can improve performance, especially on modern computers with multiple processors or cores. By dividing tasks into threads, multithreaded applications can handle complex operations more efficiently. For example, a web browser can load multiple web pages at once, while a game can process graphics and user input simultaneously. This approach enhances user experience and optimizes resource usage in systems like Windows or Linux.