Chandas gives systematic and meticulous formation of mantras and characteristics of vruttaah etc: “chandah paadau tu vedasya”. chandas is considered as legs of chandas gives beauty to mantra and it is attractive and interesting to hear. It gives singing effect to the shlokas. “chandayati prunaati ruchate iti chandas.”

vaidika chandas has no restriction on number of lines. It could be of 1, 2, 3, 4 or 5 lines/paadas. gaayatri, ushnik having 3 paadas are mostly available in vedas. 24 aksharas in gaayatri, 28 in ushnik, 32 in anushtup, 36 in bruhati, 40 in pankti, 44 in daivata, 48 in jagati, 100 in abhikruti and 104 in utkruti. If 23 aksharass are there it is called nivrut gaayatri. If two letters are less, it is called viraat. If two are more, it is called swaaraat. If one letter is less to maintain the flow, they read a word breaking by taking out a vowel in between and pronounce it separately.  For example, jeshtha is pronounced as jya yi shtha.

pingala’s chandas shaastra is considered as first granthi on chandas  shaastra and considered as vedaanga. It is of 8 chapters. This one is base for all later granthas.

The following shlokah is in avataarika of this book which explains the formation and structure of gana.

आदिमध्यावसानेषु चरता यान्ति लाघवम्।

भजसा गौरवं यान्ति मनौ तु गुरुलाघवम्॥

aadimadhyaavavasaaneshu charataa yaanti laaghavam |

bhajasaa gauravam yaanti manau tu gurulaaghavam ||

Later written granthas are:

vruttaratnaavali and shrutabodha by kaalidaasa (may not be kaalidaasa of shaakuntala); chandovichiti (7^th century) by janaashraya; suvrutta tilakam by kshemendra; (11^th century); chandonushaashanam by hemendra; (12^th century); vrutta ratnaakaram by kedaara bhattu (15^th century). Many are not yet published.

vedopakaranas: The following three nirukta, jyotisha and kalpa are called as vedaarthopakaranas.