The issue of power system load modeling has long perplexed the electrical power industry. Existing models, such as the ZIP model, widely utilized within the industry, lack a robust foundation, relying heavily on parameters derived from empirical sources. Surprisingly, these rudimentary models have endured without posing significant engineering hurdles. Yet, maintaining this status quo is growing increasingly challenging. This article presents an overview of advancements in power system load modeling spanning model structures, parameter determination, and modeling methodologies, emphasizing the dearth of research on Synthesis Load analysis as a critical challenge in load modeling. Future endeavors will pivot towards a thorough examination of Synthesis Loads. Establishing mathematical models (load model) is just a key product of it. The potential application fields could also encompass load forecasting and Virtual Power Plants(VPP).