Shudhha, Achal, Komal, and Teevra Swar

Achala Swar : The notes Shadja and Pancham are fixed on the scale. They are referred to as Achal swara (immovable).

Vikrut Swar : The other notes viz. Rishabh, Gandhar, Madhyam, Dhaivat and Nishad are Vikrut (Movable).

Komal Swar : In Vikrut swaras Rishabh, Gandhar, Dhaivat, Nishad can be moved below there shuddha place on the scale. They are called komal (Soft or Flat). These are shown by a small horizontal line below the note.

Teevra Swar : Only Madhyam, can become vikrut by going one note above the shuddha Madhyam. It is called teevra (Sharp). It is shown by a small vertical line above the note.

Shadja - Sa
Rishabh - Re
Gandhar - Ga
Madhyam - Ma
Pancham - Pa
Dhaivat - Dha
Nishad - Ni