Guṇa_ गुण =
_depending on the context means ‘string, thread or strand’, or ‘virtue, merit, excellence’, or ‘quality, peculiarity, attribute, property’.
The concept originated in Samkhya philosophy, but now a key concept in various schools of Hindu philosophy. There are three guṇas, according to this worldview, that have always been and continue to be present in all things and beings in the world_
_sattva (goodness, constructive, harmonious)
is the quality of balance, harmony, goodness, purity, universalizing, holistic, constructive, creative, building, positive, peaceful, virtuous
_rajas (passion, active, confused)
is the quality of passion, activity, neither good nor bad and sometimes either, self centeredness, egoistic, individualizing, driven, moving, dynamic
_tamas (darkness, destructive, chaotic)
is the quality of imbalance, disorder, chaos, anxiety, impure, destructive, delusion, negative, dull or inactive, apathy, inertia or lethargy, violent, vicious, ignorant
All of these three gunas are present in everyone and everything, it is the proportion that is different, according to Hindu worldview. The interplay of these gunas defines the character of someone or something, of nature and determines the progress of life.
In some contexts, it may mean ‘a subdivision, species, kind, quality’, or an operational principle or tendency of something or someone. In human behavior studies, Guna means personality, innate nature and psychological attributes of an individual.