Web services communicate with each other using standardized protocols such as SOAP (Simple Object Access Protocol) and REST (Representational State Transfer). SOAP relies on XML for message formatting and is often used in enterprise environments for its robustness and security features. In contrast, REST is more lightweight and uses standard HTTP methods for communication, making it popular for web APIs. Both approaches facilitate data exchange between disparate systems, enabling integrations, and remote procedure calls. This interoperability is essential for modern applications that rely on distributed architectures.