Going by the source (GoF book)
decorator pattern is structural and its intents are
* Attach additional responsibilities to an object dynamically
* Provide a flexible alternative to subclassing for extending functionality
An example of this is adding borders or scroll bars to a text view
For chain of responsibility pattern is behavioral and its intents are:
* Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request
* Chain the receiving objects and pass the request along the chain until an object handles it
An example of this is purchasing authorization (branch manager → regional director → vice president → president). Another is
java exception handling.