Vadi and Samvadi

When establishing a raag, 2 notes of the scale become very significant and serve as fulcrums for organising the phrases. These are called the vadi and samvadi, the samvadi being subordinate to the vadi.
They are usually at fourth or fifth intervals to each other.

Komal and Tivra

The komal swar (flattened notes) are designated with a horizontal bar beneath them. The tivra swar (sharpened notes) are designated with a vertical line over them. The only note that may be sharpened is the Ma.
These are part of the basics of Bhatkhande's notational system which is widely accepted in India although there are a few other systems which may also be found.

Aarohi and Avrohi

The aarohi are the ascending notes of the raag scale and the avrohi are the descending notes.