Jersey is a popular framework for building RESTful web services in Java. It is the reference implementation of JAX-RS (Java API for RESTful Web Services), providing tools and libraries to create scalable and efficient APIs. Jersey simplifies tasks such as request and response handling, error handling, and content negotiation. The framework integrates well with other Java technologies like Spring and Hibernate, making it a go-to choice for enterprise-level REST API development. It supports features like asynchronous processing and custom filters, providing flexibility for advanced use cases.