Okio is a modern library for handling input and output in Java and Kotlin applications. It simplifies tasks like reading and writing files, making it easier for developers to manage data streams efficiently. With its focus on performance, Okio is designed to work seamlessly with other libraries, such as Retrofit for network operations. One of the key features of Okio is its use of Buffer objects, which help in reducing memory usage and improving speed. The library also supports various data formats, including JSON and XML, making it versatile for different programming needs. Overall, Okio enhances the way developers interact with data in their applications.