Chapter – IVBASICS OF GIS4.1 Geographic Information SystemA geographic information system is a system consisting of software, hardware, data and people who analyze, modify, store, transfer information related to any position on earth. GIS is divided into the following parts: Skilled people Geographic data Software and hardwarePeople: The most important and powerful part of GIS. With the introduction of computers, they have been used for various purposes and by different experts and institutions, so with the increasing use of computers, GIS has not been limited to GIS experts. It has been used by schools, by botanists to locate and map various plant species, by hydrologists and geologists, police have used it to solve crimes, also used by disaster management authorities, etc. With the availability of various open source software and freeware the user community has increased exponentially. Data: Another important and probably more expensive part of GIS. All geographic data is entered into the software using a process called digitization, a process that involves digitally inputting various geographic features such as rivers, mountains, and land use characteristics. This can be done with a paper map attached to the map surface and this process can be very long and sometimes complicated. But then the availability of data can be facilitated by the government and other various institutions, organizations and companies by making it readily available on various platforms. Hardware/Software: Hardware is the computer and other equipment that can be used to operate the GIS. Other hardware may include routers, printers, plotters, external storage systems, etc. GIS software contains the necessary functionality for… map users by providing information on such changes that can be integrated into the policy-making structure of other regions. The creation of past climate conditions has always been the basis for future climate projections. Maps have traditionally been used to explore the Earth and exploit its resources. GIS technology, in addition to cartography, has improved the efficiency and diagnostic power of conventional cartography. Now, as the scientific community recognizes the ecological consequences of anthropogenic activities that influence the climate, GIS technology is becoming a necessary tool for understanding impacts over time. GIS makes it possible to combine various types of data with existing maps, past data and updated information from Earth observation satellites to record past evidence of change which in turn can be used to design future ecological scenarios.