describe(*args, &block)
public
Creates and returns a class that includes the ExampleGroupMethods module. Which ExampleGroup type is created depends on the directory of the file calling this method. For example, Spec::Rails will use different classes for specs living in spec/models, spec/helpers, spec/views and spec/controllers.
It is also possible to override autodiscovery of the example group type with an options Hash as the last argument:
describe "name", :type => :something_special do ...
The reason for using different example group classes is to have different matcher methods available from within the describe block.
See Spec::Example::ExampleGroupFactory#register for details about how to register special implementations.