The existence of non-profit organizations dates to ancient history when citizens worked together to solve different social issues their communities were facing. With the development of society, such gatherings were more formalized through the legal structure, usually as non-profit organizations. The importance of the existence of non-profit organizations lies in the need to respond to social, economic and political issues and to ensure the improvement of society and the community. Non-profit organizations improve living standards within their societies and do their best to advocate for those that cannot advocate for themselves. Non-profit organizations operate under various legal forms such as foundations, associations, unions, institutions and other organizations which don't make profit. As the name suggests, nonprofits do not make a profit, but that does not mean they don't earn the money. On the contrary, non-profit organizations have an interest in making a profit in order to redirect it to achieving organizational goals. The importance of non-profit organizations is unquestionable and in knowledge economies that promote democracy, development and innovation, the civil sector, of which non-profit organizations are an integral part, is becoming an increasingly important concept of cross-sectoral cooperation. Such a cross-sectoral model of collaboration is called the Quadruple Helix model, which is an updated version of the Triple Helix model in which the development of society was based on collaboration between the private sector, government and the academy. However, the role of civil society organizations in the development of society and improving the quality of life of all actors, especially marginalized groups of people, is irreplaceable because it presupposes the existence of active citizenship whose ideas, research and innovation solve social problems that the public sector (the government) cannot solve. This thesis explores non-profit organizations as an integral part of civil sector with emphasis on Association Lipa, which significantly contributes to the realization of common interests of society.