How does the mediator pattern differ from proxy?

The mediator and proxy patterns solve different problems:

• Mediator is a behavioral pattern that centralizes interaction between objects to reduce direct dependencies between them. Instead of objects communicating directly with each other, they interact through a mediator, which manages their communication.

• Proxy is a structural pattern that provides a substitute or surrogate for another object, controlling access to it. A proxy can add additional logic (such as lazy initialization, caching, access control) when calling methods on the real object.

Example:

• A mediator manages dialogue between multiple UI components so they do not depend on each other directly.
• A proxy can be an object that controls access to a remote service or protects calls to a resource-intensive object.