Parallel Streams are a feature in the Java programming language that allow developers to process collections of data concurrently. By splitting the data into multiple segments, each segment can be processed simultaneously on different threads, which can significantly improve performance for large datasets. Using Parallel Streams is straightforward; developers can convert a collection into a stream and then invoke the `parallel()` method. This enables operations like filtering, mapping, and reducing to be executed in parallel, making it easier to leverage multi-core processors for faster data processing without complex thread management.