It refers to the property of each substance that makes it different from another. Vishesha the dissimilarity breaks the unity and decreases the strength and is said Harasa Hetu Vishesha (peculiarity) decreases the things.

Classification of Vishesha

Dravya Vishesha
The concern of different dravyas is called dravya vishesh. This can be explained by the example of eating flesh that increases diet, muscles and bones but if it is other way round that is bones are consumed the muscles do not increase.

Guna Vishesha
The concern of different Gunas (property) is known as Guna Vishesha. The illustrating example is of cold water that has Sheeta Guna and aggravates Kapha Dosha while hot water suppress the Kapha Dosha.

Karma Vishesha
It is the concern of the karmas. The illustrating example is that of the decrease of kapha dosha while walking because Kapha Dosha has Achala (immobile) Karma so it is decreased or suppressed by Chala Karma walking.