GIS and Remote Sensing are tools that can be used in projects that deal with, for example, population growth, heat loss, urban heat islands, gathering population opinion about certain areas using geographical location, urban density, suitability analysis, land usage etc.
GIS is a framework for gathering, managing and analysing data about the real world. It integrates many types of data including vector (administrative regions, streets and parcels) and raster data (land usage and elevation).
Remote Sensing is the science and technology by which characteristics of objects of interest can be identified without direct contact. Satellite can obtain extensive coverage of the Earth for a long period. The reflected electromagnetic waves are received by sensors aboard platform. By understanding characteristics of electromagnetic response, we can know the size, shape and character of the objects.