Today, Relativity is becoming an integrated aspect of engineering fields. Its application to the Global Positioning System (GPS), extends in usage from smart watches to the navigation of cars, airplanes (drones) and even autonomous tractors. In rather expensive particle accelerators, physicists are everyday playing with Relativistic Billiards, common to the betatrons of cancer therapy using electrons. Computer programs, such as ray tracing methods, are enhanced to simulate objects in relativistic motion, which now offer us relativistic visualizations of accretion disks around compact, astrophysical objects like Black Holes. Against the backdrop of the applications explained throughout the chapters, this book takes on a practical and intuitive approach in introducing the Lorentz invariance of light propagation and space-time concepts. The book begins with simple mathematics, like the classical Pythagoras formula for energy-momentum triangles. Later, readers will find the intuitive vector calculus reemerging in the expansion of full relativistic expressions. Prepared with instructive diagrams of recent experiments, even the layperson can grasp the essential study of Relativity and marvel at its applications within this book.