Head of House
From Harry Potter Wiki
At Hogwarts School of Witchcraft and Wizardry, a Head of House is a teacher responsible for one of the four Hogwarts Houses. It is possible for a Head of House to serve concurrently as Deputy Head but not as Head of the school.
A Head of House must have been a member of that House while a student at Hogwarts.It is possible that a shortage of teachers who had been in Slytherin after the First Wizarding War paved the way for Severus Snape to become Head of that House at a remarkably young age for such a position. On the return to the Hogwarts Faculty of Horace Slughorn, who had been Head of House when Snape was a student, Snape jealously guarded the prerogatives of the Headship.
A Head of House is in charge of discipline over its students as well as making decisions regarding the House's Quidditch team.
A Head of House also gives their fifth years of their house advice for the student's future career.
The precise mechanism by which they are chosen is not known.
