A mezuzah is a case which is traditionally fixed to the door frame of each Jewish house in order to fulfill the words of the Torah commandment which requires that the words of the Shema Yisrael (specific verses taken from the Torah) will be attached to the doorpost. In order to fulfill this commandment, the mezuzah contains inside a small scroll inscribed with these verses. It is common for the more traditional Jews to attach a mezuzah to each door of their home and not limit themselves only to the front door. The mezuzah cases are nowadays a real work of art. They are made of wood, metal, stone, ceramics and even polymer clay and are richly decorated with Jewish motifs and drawings.
Placing the mezuzah close to the door post needs to obey several rules: it should be placed approximately 8 cm away from the door opening with lots of care in order not to damage the scroll placed inside. Any damage brought to the scroll is considered to be disrespectful of the Torah (since the words of the Torah are inscribed on these scrolls). In this regard, once the family moves, they should remove the mezuzah as well, in order to prevent the next owners from disrespecting it. Another rule refers to the very placement of the mezuzah on the doorpost. Ashkenazi Jews place its slanted towards the room one is entering. Such a slanting position is also preferred by the Spanish and Portuguese Jews. Others prefer to place it either vertically or horizontally.