A mezuzah is a piece of parchment usually contained in a decorative case, inscribed with specified Hebrew verses from the Torah. These verses contains the Jewish prayer "Shema Yisrael", beginning with the phrase: "Listen, Israel, the Lord is our God, the Lord is One."
It is affixed to the doorframe of Jewish houses to fulfill the mitzvah to inscribe the words of the Shema "on the doorposts of your house". Many families place a mezuzah only on the entrance door, but observant Jews affix one on every doorway in the home apart from bathrooms, as well as closets too small to qualify as rooms.
According to halakha, the mezuzah has to be placed on the right side of the door, in the upper third of the doorpost
The Decorative Mezuzah Cases you see here are Unique and contemporary works of art