Soft skills called in different ways (non-cognitive skills, non-technical skills, generic skills...), are skills that develop throughout life. The study of these skills remains unclear in current research with weak theoretical frameworks, sometimes, evoking a non-conscious learning of these skills while others link them to personality traits. Nevertheless, these soft skills are characterized by their vast field of application, linked to both personal and professional life. They are mainly interpersonal, intrapersonal, emotional, methodological skills and/or meta-skills that contribute to the efficiency of various tasks. Strongly favoured by the labour market, the acquisition of these skills is the subject of growing number of studies. However, there is a lack of consensus on their definition and naming, mainly due to the very varied theoretical fields (marketing, economics, sociology...). These various terms, give rise to different meanings that generates confusion. Therefore, the aim of this communication is to clarify the concept of soft skills through a critical study, to categorize the different types of soft skills mentioned above and to show how processes underlying these skills refer to processes and metacognitive knowledge. In this context, we will present the current research to better understand the acquisition and application of soft skills within an adult learning organization. Indeed, our ongoing research will allow us to lead understand the acquisition of soft skills and to identify whether this direction of research supports the need for an awareness of one's own cognitive functioning. Consequently, we will develop how considering metacognition in research of soft skills could remedy the theoretical gaps.