The word GIS stands for Geographical Information System. It is a technology that gives us information about various things and places on the earth's surface or we can even define it as a technology that is used to view and analyze data from a geographic/ geospatial perspective. Similarly, there is a software known as QGIS previously known as Quantum GIS which helps in making maps or you can say that it plays a major role in the map projection.
The QGIS is very useful for the Thematic maps. The basic files used in creating maps are:
- Raster
- Vector
In raster files, images contain in the form of pixels, or cells, whereas vector files Points, Lines and Polygons for making images.
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| HOW TO USE POINT, LINE AND POLYGON IN A MAP? |
- Point: It is used to specify a particular thing or position on the earth's surface, specially used in GPS for the positioning. It is also known as a coordinates that shows the exact location which is very helpful in making maps. The smallest geographical features are well specified by the points where lines and polygons cannot be used. The point is a mark or dot used in the starting and at the end.
- Line: It is used to show the narrow features on the map or you can say the length of the features like road, railway, streams, etc. Lines show the shape and direction which is in more detailed manner that it easier for the users.
- Polygon: It is used to show a particular area or geographical features like a state, particular district, wetland, agriculture, forest, etc. Polygons are the series of nodes that are joined together. The starting and the ending point is the same that means when we draw a polygon we have to end at the same node from where we started.
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