Biochar, an organic, porous, and carbon-rich material originating from biomass via pyrolysis, showcases compelling attributes and intrinsic performances. Its appeal as a reinforcement material for biocomposites, as well as its auspicious electrical properties, has gained more attention, and makes biochar a versatile candidate for applications ranging from energy storage to catalytic devices. This scientific review undertakes a comprehensive exploration of biochar, spanning production methodologies, physicochemical intricacies, and critical process parameters. The focus of this paper extends to optimization strategies for biochar properties tailored to specific applications, with a dedicated inquiry into diverse production methods and activation strategies. This review’s second phase delves into a meticulous analysis of key properties within biochar-based composites, emphasizing limitations and unique performance characteristics crucial for diverse applications. By synthesizing a substantial body of research, this review aims to catalyze future investigations by pinpointing areas that demand attention in upcoming experiments, ultimately emphasizing the profound potential of biochar-based materials across technical and scientific domains.