Blood status, also called purity of blood, is a concept in the wizarding world that distinguishes between family trees that have different levels of magically-endowed members. It often results in prejudice towards those who have a large number of Muggles in their families. Wizarding society in general considers itself apart from and superior to Muggle society, which is not connected with magic. As Sirius Black informed Harry Potter, almost all wizards of their time have Muggles in their family trees, though some claim not to. The concept played a key role in both the First and Second Wizarding Wars. In truth, pure-blood families have ceased to exist during the 1900s.