Welcome to the wonderfull art of Transfiguration! If you read this Topic, everything will be clear for you about this class. Transfiguration isn't easy, but if you study hard, then you can easily pass your exams.
Transfiguration is a branch of magic that focuses on the alternation of the form or apperance of an object, via the alteration of the object's molecular structure. Transfiguration can be done to most (if not all) objects and as with most forms of magic it includes - but hardly limited to - Transfiguration spells, which comprise the one of the seven known spell types.
Classification:
Currently, Tranfiguration is divided into four branches. They are, in ascending order of difficulty: Transformation, Vinishment, Conjuration and Untransfiguration.
Transformation:
Transformation is divided into three sub-types. Human Transfigurations (think of Animagus, Metarmorphmagus and Werewolf), Switching and Trans-species Transformations.
Vanishment
This is the art of causing things to vanish, to make things go into non-being.
Untransfiguration:
It's the art of reversing a previous transfiguration.