While silicon pixels is the commonly chosen technology for measuring particle trajectories in the high track density environment of modern HEP detectors, the planned detector upgrades and next generation of experiments pose stringent requirements on the inner detector systems. A large variety of silicon pixel detector technologies have been developed to address the specific needs of these diverse use-cases. There are, though, common detector needs: Thin sensors, small pixels, precise timing, complex in-pixel processing capabilities together with low power consumption while being operated in high radiation environments. In this talk, I will briefly describe the historical evolution of silicon detectors for high energy physics applications and its basic principles, giving an overview of the most promising evolution for future HEP projects given the aforementioned mutually exclusive characteristics.