Apache Axis2 is a Java-based web service engine that provides a framework for creating and consuming web services. It supports a variety of protocols, including SOAP, REST, and HTTP, and can be used for both client and server applications. Apache Axis2 is an open-source project developed by the Apache Software Foundation, and is widely used in enterprise applications for its robustness, scalability, and flexibility. It requires specialized knowledge of Java programming and web services architecture.