Basics of Carnatic Music

There are 7 notes in Carnatic music, these are Sa, Ri, Ga, Ma, Pa, Da and Ni.
These are also called sapthaswaras (saptha means seven , swaras mean notes).
Every song has a shruthi (pitch) in which it is rendered.
This shruthi is comprised of 3 notes - either Sa, Pa , Sa (for panchamam-based shruthi) or Sa, Ma, Sa for madhyamam-based shruthi.
A raga is a combination of swaras in the Aarohana (ascending order of swaras) and Avarohana (descending order of swaras).