2.5. Metadata

     Metadata is data about the data. It consists of information that describes spatial data and is used to provide documentation for data products. For example, metadata describes the format, geographic boundary, projection, coordinate system, availability, and cost, etc., of a spatial data set. Metadata is the who, what, when, where, why, and how of spatial data. The key purpose of metadata is to facilitate and improve the retrieval and sharing of information. They are integral part of GIS data and are usually prepared and entered during the data production process. Metadata is important to anyone who plans to use public data for a GIS project.  Metadata is also needed to determine whether a data set will satisfy the user's requirements with respect to spatial resolution and data quality. In the case of remotely sensed images, metadata may include the percentage of cloud obscuring the scene, or whether the scene contains any specific phenomena, such as hurricanes.

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