This article provides a synopsis of the Multimodal Social Semiotic theory and its underpinnings in semiotics and social semiotics. It outlines the development of Multimodal Social Semiotic theory, tracing the broader theoretical structure from which this approach originates to enhance the understanding of its foundational principles and evolution. Given that the theory is primarily social-semiotic, this study discusses the constituent parts of the theory, starting with social semiotics. The starting point is with the objectives of social semiotics and its foundations in Functional Linguistics. Next, a discussion of the essential problematic issues in semiotics in contrast to social semiotics is tackled. Kress and Van Leeuwen's model of visual grammar is then recapped. What follows is an outline of the main assumptions and concepts of multimodality. Thereupon, social semiotics is discussed by showing its development as an approach within multimodality concerning its main concepts, such as semiotic resources, interest and design.