The current training course is the first one in a 3-levels full training under the broad topic “Basics and Applications of the Global Navigation Satellite Systems: GNSS”. This first course presents the basics of geodesy in a general perspective prior to discussing satellite geodesy in particular. Definition and applications of geodesy will be presented first, Then, fundamentals of the figure of the Earth, geodetic datums, coordinates systems, satellite positioning, and data analysis will be explained.