Arohanam and Avarohanam

What is a Raaga ?
Literally the term raaga means a melodic and intricate combination of swara phrase which is appealing and pleasing to all. Just as colour tinges the cloth, the permutations and combinations of svara phrase tinges the minds of the living beings, both human and animal. It is capable of creating a sweet and soothing effect. Raga can be compared to a language having its alphabets and phrases as different svara combinations.

A raaga is the combination of appropriate swaras in the Arohana and Avarohana.

Arohanam and Avarohanam
Arohanam is the sequence of swaras used in a raaga in the ascending passages i.e. as the pitch goes up starting from lower 'Sa', Ri, Ga and so on. Avarohanam is the sequence of swaras to be used in descent. Starting from the higher 'Sa' , 'Ni', 'Da' and so on.

The arohanam and avarohanam of a raaga provide only a skeletal outline upon which the rest of the raaga is formed.