Mulavar or Mula-murti is a Sanskrit-Tamil term referring to the main deity, or a murti in a Hindu temple.
Mulavar of Pandurangaswamy Temple
A garbhagriha, also known in Tamil as a moolathana or karuvaṟai, is the innermost sanctuary of Hindu and Jain temples, often referred to as the "Holy of Holies" or "sanctum sanctorum".
Moolavar
…while the mulavar image is moved to a temporary location. The practice is called Balalayam, during which a temporary image is housed in the sanctum. Garbhagriha (lit. womb chamber) is a Sanskrit word referring to the interior of the sanctum sanctorum, the innermost sanctum of a Hindu temple, where resides the…
Devotees offering prayers at the garbhagriha in Chennakeshava Temple, Belur, which houses the icon of the god Vishnu.
Garbhagriha at Pattadakal with the Lingam icon of the god Shiva.
A schematic of a simple Hindu temple showing the garbhagriha sanctum, antarala and mandapa
Architecture of a Hindu temple (Nagara style). These core elements are evidenced in the oldest surviving 5th–6th century CE temples.