In an era where robots are increasingly becoming part of our daily lives, we still struggle to define exactly what constitutes a robot. Do robots deserve to be defined by biological markers? How can we differentiate between a mechanical android versus one with synthetic skin? Are robots simply advanced machines that serve as tools for humanity? Will they eventually join the fabric of human society as our agents, advisors, assistants, maids, nurses, and partners? Will they be our servants, equals or superiors? Will we merge with them to become human-robot hybrids? When robots become superintelligent will they be regarded as sentient? How can we even define sentience? What is a robot? Systema Robotica aims to answer these questions and serve as humanity's guide to a better understanding and coexistence with robots in a future of non-human superintelligences. The treatise defines the true nature of robots, classifies three evolutionary realms of intelligences, structures a definitive robot taxonomy, explores the role of robots within society, and introduces a novel definition and test for sentience.