Independently on the origin and background, chances are happiness is on the person’s list of priorities. Happiness has been said to reflect the ultimate purpose of human existence for which efforts and energy are directed. People strive toward a happy and meaningful life but reaching the state does not follow one exact path. A widely sought-after universal receipt for happiness remains undiscovered. As many people so many ways to pursue happiness. This is because while happiness is clearly perceived when experienced, it is difficult to examine and evaluate. Centuries of ongoing interest supported by research conducted in different scientific disciplines still bring new findings and open the door to further research work. In this paper, we present theoretical foundations of happiness and provide a range of perspectives that delineate the understanding of happiness. We present the main characteristics and key determinants that manifest in happiness studies and discuss challenges of embracing and measuring happiness in the modern world. <br> Keywords