This chapter focuses on the Parabolic Solar Trough Collector (PTC), a highly efficient technology for capturing solar thermal energy by concentrating sunlight onto a receiver tube. It begins by tracing the historical development of PTCs and their growing role in sustainable energy systems. A comprehensive literature review is presented, analyzing thermal and optical performance as well as highlighting the strengths and limitations of traditional designs. The technical aspects of PTC construction are explored in detail, with attention to key parameters that influence energy efficiency. The chapter also discusses a wide range of practical applications, including power generation, industrial process heat, refrigeration, and air-conditioning. With increasing global emphasis on clean energy, this chapter underscores how PTCs contribute meaningfully to reducing fossil fuel dependence and mitigating climate change.