What is a Mezuzah?
A mezuzah, mounted on the doorpost, designates the home as Jewish reminding us of our connection to G d and to our heritage. Although Many use the term "mezuzah" referring to the decorative case in which the Mezuzah is often housed, the mezuzah is essentially the parchment scroll within, on which the "Shema" - a biblical passage declaring the oneness of G d - is handwritten by a trained scribe.
The mezuzah is also a symbol of G d's watchful care over the home. The name of G d, Sha-dai, which appears on the reverse side of the parchment, is an acronym for the Hebrew words which mean "Guardian of the doorways of Israel." The placing of a mezuzah on the doors of ones home or office protects the inhabitants - whether they are inside or outside.