Wikipedia
Ratha ( Sanskrit: रथ, , Avestan raθa) is the Indo-Iranian term for a spoked-wheel chariot or a cart of antiquity.
The Rigvedic word rá-tha does not denote a war-chariot like those of Andronovo, Egypt, Greece, and Rome. The word is from √ṛ ‘go’ giving primary rá-tha ‘a goer, car, vehicle’. Similar formations exist with the suffix -tha: ártha ‘goal’, ukthá ‘saying’, ǵāthā ‘song’ etc. The rigvedic ratha is described as pṛthu ‘broad’ 1.123.1; bṛhat ‘tall, big’ 6.61.13; variṣṭha ‘widest’ 6.47.9. It has space not for 1 only or 2 (i.e. the driver and the warrior with his spear and bow) but for 3: it is said to be trivandhurá (1.41.2; 7.71.4) and then to carry 8 aṣṭāvandhurá (10.53.7)
In Hindu temple architecture, a ratha is a facet or vertical offset projection on the tower (generally a shikhara).
In Sanskrit, the word "ratha" means "chariot", but the link with this meaning is not clear.
The rathas are decorated with geometric figures or statues, such as statues of a gatekeeper watching outside or a niche with a statue of a deity.
Sometimes, the facet of the ratha is hollowed to the interior; these are rathas with recesses.
If there is only one facet, this is a temple with three rathas (triratha): the wall and the facet on the left and on the right.
If there are a main facet and a secondary one, the temple has five rathas ( pancharatha). There are also temples with seven rathas ( saptaratha). and nine rathas (navaratha).