When you talk about notes
Indian classical music has two fundamental elements, Raga and Tala.
The raga, based on a varied repertoire of Swara
In Hindustani music
Swar : S,R,G,P,D,N,S there are Achala, Vikrut, Komal and Teevra.
Saptaks: Octaves in Hindustani music
Raags is derived from a Sanskrit word which means ‘to bring delight’ They are also capable of evoking emotions like anger, sorrow, love, passion, and devotion
Alaap: An Alaap is the rendition of a Raag, emphasizing on the prominent features of that Raag.
Alaap rendered in a slow tempo, and convey every essence of a Raag.
Taan — Using different combinations of the Swars of a Raag, in a fast tempo, a Taan is rendered by the musician and it is a tribute to their talent, practice, and their overall training.
Ras — the mood of the Raag and the essence of its being.
i.e. Malhar category, are only sung during a specific season like during the Monsoon season.
Thaat-"Parent scale" in North Indian or Hindustani music. The concept of the thaat is not exactly equivalent to the western musical scale because the primary function of a thaat is not as a tool for music composition
Alankars,
Alankar or Alankara means ornaments or adornments. In the context of Indian classical music, the application of an alankar is essentially to embellish or enhance the inherent beauty of the genre. ... This classification of alankars related to the structural aspect of a raga.
by : Jacintha - study on Internet
