1. Orthographic projections are a method of technical drawing where different views of an object are projected onto horizontal, vertical, and side reference planes. 2. There are three main views: the front view projected onto the vertical plane, the top view projected onto the horizontal plane, and the side view projected onto the profile plane. 3. The document provides examples of how to select views, orient objects, and draw orthographic projections according to first-angle or third-angle projection systems.