Every language has its own rules for syntax and grammar. And music is no exception to this fact. Indian Classical Music had long been an 'Oral' form of art, devoid of any form of documentation or recording. Fearing that this rich aspect of our culture might diminish in the centuries to come, scholars argued for a standardized system of notation to represent the different tones and beats of music that could be easily documented and reproduced. 

The biggest challenge to this consensus was defining symbols that could represent the different frequencies used. The earliest proposal was to define each single frequency as a 'Naad', which meant that there were infinite Naads in one octave. But soon realizing that more discrete and absolute notes had to defined, 22 distinct 'shrutis' were created. These shrutis were placed at intervals of frequencies such that they were distinguishable to the human ear, and the Ragas and other compositions could be appropriately represented by these 22 shrutis. 

Despite the widespread popularity of the concept of shrutis, it was soon realized that the audience for music (common man with little expertise in music) could not easily distinguish between the shrutis, and two consecutive shrutis seemed a single note to most of them. This led to the creation of 12 'swars', a concept in use even today. 

In the years to come, different music notation systems emerged that could comprehensively represent all compositions with symbols. The two main systems were Bhatkhande Notation System (popular in Northern India) and Paluskar Notation System (popular in Southern India).

Here's a list of the basic differences in these notation schemes: