Jyotish is the eyes of the Vedas. It has many divisions like Ganitham, Jathaka, Kola, Prasannam, and Nimittham. Jamakkol Arudam comes under the division Prasannam. Prasanna Jyotish is of many types like Deva Prasannam, Ashta Mangala Prasannam, Aruda Prasannam. Sozhi Prasannam (Sozhi means Cowrie Shells), Swarna Prasannam (Svarna means Gold); Thambula Prasannam (Thambulam means Betel leaves with Betel nuts); K.P Horary Prasannam, Pancha Pakshi Sastra Prasannam. etc. There are many types of Prasanna using various types of calculations. Mostly the names of the Prasannam reflect the method used for prediction. For instance take for example Sozhi Prasannam; here Cowrie shells are used hence called Sozhi prasannam. Ja- makkol Arudam, Jaamam or Jamam is used for calculation, hence it is called Jamakkol Arudam. Jamam is a division of a day into 16 parts. 8 parts in the day. 8 parts in the night follow an order. Kol means Planets in Tamil, Arudam means which place he sits or stands or positioned, hence the name Jamakkol Arudam. Lord Shiva is called Rishaba Arudam- means the one who sits on the Rishaba-Bull.