
Thus the word mezuzah can refer to any of the following:
Simply a door post of a permanent door, gate, or arch.
The special parchment with the required Hebrew inscriptions.
The small case or box that typically covers the parchment. (The parchment can be affixed directly to the door, though usually a case is used in order to protect it. It is important to be aware, though, that a case without a valid mezuzah scroll inside cannot be used to fulfill this mitzvah.) The case generally features the Hebrew letter shin (ש) inscribed on its upper exterior. Artistic mezuzah cases are often given as gifts for weddings and other special occasions.