This lecture covers the concept of projections in geomatics, focusing on different types such as conical, azimuthal, cylindrical, and more. It explains how projections deform the Earth's surface to create maps and plans, emphasizing the importance of choosing the right projection for specific applications like navigation. The Swiss projection, adopted in 1903, is discussed in detail, highlighting its characteristics and practical use in representing geographic features accurately. The lecture also addresses issues like linear strain, meridian convergence, and the significance of preserving angles in map projections.