Protego is a spell from the Harry Potter series, created by author J.K. Rowling. It is known as the Shield Charm, designed to create a magical barrier that deflects spells and physical entities. When cast, it provides protection to the witch or wizard, allowing them to defend against various magical attacks. The charm is often taught to young witches and wizards at Hogwarts School of Witchcraft and Wizardry. While it is effective against many spells, it may not hold up against the most powerful magic. Mastery of Protego can enhance a wizard's defensive capabilities in duels and dangerous situations.