Aron Kodesh comes from Hebrew אָרוֹן קׄדֶש ʼārōn qōdeš (i.e. aron kodesh), Holy Ark. This name is a reference to the ’ārōn haqqōdeš, the Hebrew name for the Ark of the Covenant which was stored in the Holy of Holies in the inner sanctuary of both the ancient Tabernacle and the Temple in Jerusalem. Similarly, Hekhál, also written hechal, echal or heichal — and sometimes also Echal Kodesh (mainly among Balkan Sephardim) comes from Hebrew הֵיכָל ‘palace’, was used in the same time period to refer to the inner sanctuary. The hekhal contained the Menorah, Altar of Incense, and Table of the Showbread.
The ark is often placed on the wall of the sanctuary which is facing Jerusalem, however it is sometimes placed on the north wall or another wall for architectural reasons. In those cases where the ark does not show the direction to Jerusalem, traditional Judaism instructs the worshiper to face the true direction towards Jerusalem in prayers such as the Amidah.
In some ancient synagogues, such as the fifth-century synagogue in Susia, the Torah scroll was not placed inside the synagogue at all, but in a room adjacent to it, signifying that the sacredness of the synagogue does not come from the ark but from its being a house of prayer. The Torah was brought into the synagogue for reading purposes.
Beth Jakov synagogue in Macedonia