Micro-lattice structures have emerged as a revolutionary class of materials, combining exceptional mechanical properties, ultra-low density, and multifunctional capabilities. Their unique architecture enables superior strength-to-weight ratios, energy absorption, and thermal management, making them highly attractive for aerospace, biomedical, and energy applications. This review comprehensively examines the fundamental properties, fabrication techniques, and diverse applications of micro-lattice structures, while identifying the key challenges and future research directions. The study highlights the mechanical, thermal, and functional characteristics of micro-lattices, emphasizing the factors behind their outstanding performance, including their geometric design, material composition, and manufacturing precision. Advanced fabrication methods, such as additive manufacturing and self-assembly techniques, are explored, showcasing recent breakthroughs in scalable production. Despite their potential, challenges persist in achieving cost-effective large-scale manufacturing, optimizing multifunctional integration, and ensuring structural reliability under extreme conditions. This review addresses critical research gaps and proposes potential solutions to enhance micro-lattice technology for real-world deployment. Emerging trends, such as bioinspired designs and smart material integration, are discussed as pathways for next-generation innovations. By consolidating the current knowledge and outlining future prospects, this study aims to guide researchers and engineers in advancing micro-lattice systems. The findings underscore the transformative impact of micro-lattices in modern engineering, offering a foundation for pioneering material developments across industries.