Chhanda deals with the analysis of the types of meter used in the construction of various Vedic hymns. Chhandashastra of Pingalanaga is considered to be the oldest text available on the subject. It was probably composed between 6th and 5th Century BC. In Sanskrit, the metrical unit is known as pada (foot). Depending upon  the number of syllables used, a pada may be of the length ofeight, eleven or  twelve syllables, known as gayatri, tristubh and jagati respectively. There are other metrical schemes and further variations in the classification of the padas (meters) depending upon different criteria, the discussion of which  is outside the scope of this article. The knowledge of the Chhanda proved useful in the composition of the smriti literature. It also played an important role in the emergence of classical Indian music and Sanskrit poetry besides providing a frame work of reference for compositions in other languages.