Java Streams are a feature in the Java programming language that allow developers to process sequences of data in a functional style. They provide a way to perform operations like filtering, mapping, and reducing on collections of data, such as lists or sets, without the need for explicit loops. This makes the code more concise and easier to read. Streams can be created from various data sources, including collections, arrays, or I/O channels. They support operations that can be executed in parallel, enhancing performance for large datasets. Overall, Java Streams simplify data manipulation and improve code efficiency.