How do Concepts differ from Interfaces?

Question

How do Concepts (ie those recently dropped from the C++0x standard) differ from Interfaces in languages such as Java?

Answer 1

It's more or less a difference in the point of view. While an interface (as in C#) is specified similar to a base class, a concept can also be matched automatically (similar to duck-typing in Python). It is still unclear to which level C++ is going to support automatic concept matching, which is one of the reasons why they dropped it.