() is a concept in Hinduism and Sikhism, which can be translated as "quality, peculiarity, attribute, property". The concept is originally notable as a feature of Samkhya philosophy. The gunas are now a key concept in nearly all schools of Hindu philosophy. There are three gunas, according to this worldview, that have always been and continue to be present in all things and beings in the world. These three gunas are called: (goodness, calmness, harmonious), (passion, activity, movement), and (ignorance, inertia, laziness). 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. Like all Sanskrit technical terms, guṇa can be difficult to summarize in a single word. Its original and common meaning is a thread, implying the original materials that weave together to make up reality. The usual, but approximate translation in common usage is "quality". Terminology Guna appears in many ancient and medieval era Indian texts. Depending on the context, it means: string or thread, rope, sinew, chord (music, vowel phonology and arts literature) virtue, merit, excellence (dharma and soteriological literature) quality, peculiarity, tendency, attribute, property, species (sastras, sutras, the Epics, food and analytical literature) The root and origins Guṇa is both a root and a word in Sanskrit. Its different context-driven meanings are derived from either the root or the word. In verse VI.36 of Nirukta by Yāska, a 1st millennium BC text on Sanskrit grammar and language that preceded Panini, Guṇa is declared to be derived from another root Gaṇa, which means "to count, enumerate". This meaning has led to its use in speciation, subdivision, classification of anything by peculiarity, attribute or property. This meaning has also led to its use with prefixes such as Dviguna (twofold), Triguna (threefold) and so on. In another context, such as phonology, grammar and arts, "Guṇa-" takes the meaning of amantrana (आमन्त्रणा, addressing, invitation) or abhyasa (अभ्यास, habit, practice). In the Mahabharata Book 6 Chapter 2, the meaning of guna similarly comes in the sense of addressing each part (the root implying amantrana),