Guṇa (Sanskrit: 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 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: sattva (goodness, constructive, harmonious), rajas (passion, active, confused), and tamas (darkness, destructive, chaotic). 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.