The slowdown of Moore's Law and the breakdown of Dennard scaling have compelled the semiconductor industry to seek new paradigms for building powerful and efficient computing systems. A leading solution is the chiplet-based architecture, which abandons the monolithic System-on-Chip (SoC) approach in favor f integrating smaller, specialized dies—known as chiplets—within a single package. This method, termed Heterogeneous Integration (HI), improves manufacturing yield, reduces cost, and allows for the "mix-and-match" of optimal process technologies for different functions. However, this shift introduces critical challenges in interconnect design, thermal management, and system security. This paper reviews the foundational technologies enabling modern chiplet systems, including 2.5D and 3D packaging, and analyzes emerging interconnect standards like Universal Chiplet Interconnect Express (UCIe). We also discuss the pivotal role of AI/ML in design automation and explore future directions such as co-packaged optics and sustainable design. Finally, we provide an outlook on the evolution towards an open, interoperable chiplet ecosystem