The study of Global Positioning and Remote Sensing applications is enlightening, challenging, and very interesting. This book is created as a guide to students who are interested to know the basic principles and applications of Remote Sensing and GIS in the geosciences field. The trends and availability of high-resolution remotely sensed data are explained. The chapter then describes how to bring GPS and remotely sensed data into a GIS. Remote sensing, via aerial and satellite imageries, provides one of the most successful components of geospatial technologies. Based on the spatial resolution of remote sensing systems, remotely sensed data can be categorized into three groups: low-resolution data (>30 m), medium-resolution data (5-30 m), and high-resolution data (<5m). Sensors can be classified as active and passive, and both are used for water resources applications. The electromagnetic radiation (EMR) spectrum includes visible light, X-ray, UV, infrared, thermal, and radio waves. Remote sensing applications for water resources use visible, infrared, thermal, and radio waves. GIS applications are now considered an important course in the curriculum of undergraduate geoscience, environmental, and in some fields of engineering programs.