How does std::unordered_set compare to std::set ?

What are the differences between std::set and std::unordered_set ?

Here is a graphical and quantitative explanation of 

• how unordered_set works, 
• how fast it can access data, 
• how much memory it occypies, and 
• how it compares to std::set.

Generic C-Trees and C++ std::maps

How many lines of code do I need, to set up a typical tree structure? What are the pros and cons between a C-style generic tree and an std::map or an std::set ?