Main differences between Decorator and Proxy design pattern are:
- Decorator provides an enhanced interface after decorating it with additional features. Proxy provides same interface since it is just acting as a proxy to another object.
- Decorator is a type of Composite pattern with only one component. But each decorator can add additional features. Since it is one component in Decorator, there is no object aggregation.
- Proxy can also provide performance improvement by lazy loading. There is nothing like this available in Decorator.
- Decorator follows recursive composition. Proxy is just one object to another object access.
- Decorator is mostly used for building a variety of objects. Proxy is mainly used for access to another object.