All Ayurvedic preparations are made with herbs & some special products which contain natural minerals. Since Ayurveda studies Dravya (Substances) with the aim of the use and application of Dravya as food and medicine, the knowledge about their properties is enough to determine the utility of each substance. According to Ayurveda the utility of a substance depends on their qualities & all herbs possess 5 qualities:

Rasa (Taste)

All living things cntain the 5 Great Elements, therefore the food we eat is also comprised of these Elements, with a predominance of 1 or 2. Different combinations of the Elements confer different attributes, or properties, on food, thus our food has the important attribute of Shad Rasa
(Six kinds of Taste):

“Svadu (madhura, sweet) amla (sour), lavana (salty),
 tikkta (bitter), sna (or katu, pungent) kashaya (astringent, or dry aftertaste)
 are the six tastes present in the substances.”
[AS.Su.1/33a]

Guna (Quality)
Another property which is inherent in food substances is Quality & each Taste has a predominancy of Qualities. Substances taken as food or medicine can correct the imbalance of Doshas. This is due to the Qualities, as the qualities of food or medicine increases the dosha which has the same elemental qualities. There are 20 Qualities of food, here listed next to their opposites & counterparts:

Virya (Effect)
This is another group that all natural foods are divided into, according to their Individual effect. Substances have the potency to manifest work, so each Taste also has specific actions upon the body. The effect of food are mainly classified into 2 Qualities, which are present in abundance and hence behave differently:

Ushnaveeryam (Heating)
Katu (Pungent or Hot, Amla (Sour) & Lavana (Salty) foods have the effect of heating the body.
Pitta dominance or excess of pitta can be dealt with cooling food or medications.
Seethaveeryam (Cooling)
Madhura (Sweet), Tikta (Bitter) & Kasaya (Astringent) foods have the effect of cooling the body.
A Vata dominat person may benefit from heating food or herbs.

Vipaka (Taste after digestion)
In the Kriya (Physiology) of Ayurveda each stage of digestion is characterised by the predominant Taste. The Ahara (food) is digested by the Agni (Digestive fire or digestive activity) & knowledge of the post-digestive effects are needed in understanding physiological changes. From an Ayurvedic Pharmaceutical point of view, the Vipaka is the most important as it has no taste & thus can only be perceived by its bodily action. The qualities of food after it has undergone digestion get transformed into 3 Tastes:

Sweet & Salty becomes Madhura (Sweet)
Sour becomes Amla (Sour itself)
Pungent & Astringent becomes Katu Pungent)

Prabhava (Potency to perform action)
This potency is the power of substances to manifest work in its unique way. When Taste, Quality, Effect & Taste after digestion in a substance is found to be the same as in another substance, but in their overall action the two substances differ, it is said that the change is due to the 'prabhava' of that substance. Sometimes, Prabhava is also used to denote an "Unknown" effect of a herb; an effect we cannot explain.