The meaning of Alankar is ornament.
Like ornament increase physical grace, in the same way with Alankar there is a grace in singing.
Alankar is also called as Palta.
In the initial stage of learning Hindustani Classical Music students are primarily taught Alankars,
because without Alankar student cannot gain good swar knowledge and neither can get success in Indian classical music.
With Alankar we also get help in Raag Vistar.
A raag can also be decorated with the help of Alankar.
Taan etc are also made with the help of Alankar.
Therefore Alankar’s are practiced to gain swar gyan (knowledge) and to improve vocal abilities.
Alankars are decided phrases of swaras which covers whole saptak,
Alankars are made with Varna combinations for example we will take a Varna combination (Sa Re Ga). Now to make Alankar we will take this Varna as step.
If we start making Alankar with the first step as (Sa Re Ga) then the second step will be (Re Ga Ma) and then the third step will be (Ga Ma Pa) and it goes on till it ends at Taar Saptak Sa to complete it Aaroh.
similarly the first step for the avroh will be (Ṡ ni dha) and the second step will be (Ni Dha Pa) and then the third step will be (Dha Pa Ma) and it gose on till it ends Madhya Saptak Sa.
In this way 100s and 1000s of Alankars can be made.
Alankars can also be made by including Komal and Tivra Swars but we have to be careful that we have to use only those swaras that are present in that particular Raag, for the Raag which we are making the Alankar.