The Fork/Join framework is a parallel programming model in Java designed to efficiently process large tasks by breaking them into smaller subtasks. It utilizes a work-stealing algorithm, allowing idle threads to "steal" tasks from busy threads, which helps balance the workload and improve performance. This framework is particularly useful for tasks that can be divided into independent subtasks, such as in divide-and-conquer algorithms. It simplifies the development of parallel applications by providing a high-level API, making it easier for developers to leverage multi-core processors without dealing with low-level thread management.