The sense of security constitutes one of the fundamental human needs. Due to the crucial role that security plays in the contemporary world and its impact on states, societies, and individuals, it is often a subject of analysis in scientific literature. The article focuses on the definition of security and its evolution in the context of the individual and society. The security of modern humans is a complex, dynamic phenomenon that goes beyond traditional areas of threats, requiring redefinition in the context of changing social and technological realities. Within this research, the views of representatives from various scientific disciplines are presented, and a new definition of the concept of security is proposed. The author suggests their own definition of security as a state of mind, dependent on the satisfaction of needs in various dimensions (material and immaterial) and in relation to the individual or collective. The dynamic nature of security and its connection to the individual's perception of threats and situations is emphasized.