What exactly are C++ modules?

Question

I\'ve been following up C++ standardization and came across C++ modules idea. I could not find a good article on it. What exactly is it about?

Answer 1

Here is one of the first propositions : http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1778.pdf

And a very good explanation : http://clang.llvm.org/docs/Modules.html