Day by day, civil society organizations (CSOs) are becoming an increasingly important factor in all areas of the socio-economic system. The interest in their study has also increased, although the place, role, and definition of their terminology and concepts, needs to be further clarified, as their meaning changes conditionally. Through content analysis, this article reviews the literature by addressing a sample of 136 journal articles published in the period 2015-2019 in two big databases. The findings show that CSOs literature is dominated by qualitative works of social sciences authors who mostly use the term Non-Governmental Organizations (NGOs). This paper is also elaborated on the main themes which dominate the text of the articles. Furthermore, the main concepts of this literature, development, organizations, international, local and other words are analyzed here. The significance of this study is that it aims to provide CSOs researchers with a clearer description of the terminology and concepts the most commonly used.