SDIs are composed of three different types of information: spatial data and metadata services. These three components ordered and structured by standards, rules and regulatory framework, such as the INSPIRE Directive, form the network of Spatial Data Infrastructures.

Spatial data: spatial data can be purely topographical or thematic.

a) Topographic, "The topographic mapping collects, processes and prepares terrain data. It relies on basic sciences such as geodesy, photogrammetry and remote sensing to determine the shape and size of the earth's surface and represent a plane "(Principles of Thematic Cartography IGAC., 1993).

b) Thematic mapping: "The thematic cartography collects and develops qualitative and quantitative primary data and processes in order to disclose information about a subject or specific science (population, land cover, cadastral, cultural, economic, and other ) under a spatial representation through graphical maps, charts and profiles. They must meet in order to evoke in the reader's mind a clear and accurate picture of the phenomenon of the space environment "(Principles of Thematic Cartography IGAC., 1993).

Services: features are accessible through interoperable telematics technology offers the user an IDE to interact with geographic data. These features are organized into five types of services: search, viewing, downloading, processing and access. The geographic service standards most common are:

a) WMS (map service): Information is displayed as images composed of one or more layers and generated from vector or raster spatial information.

b) WFS (Object Services): Provides information on data layers in which it is composed of vector objects. El acceso se produce mediante el formato GML. Access is via the GML format.

c) WCS Services (coverage): This service is similar to WFS but the information shown is raster.

d) CSW (Catalog Service): Allows you to find geographic information from queries based on metadata.

e) WFS-G (or Gazette Nomenclator Service): Allows you to locate geographical entities from queries by name. Relaciona el lugar con las coordenadas que la definen. Relate the location with the coordinates that define it.

Metadata: Metadata is data associated with the information produced, which reflect primarily descriptive characteristics of these (date, origin, author, coordinate system, ...). Metadata are an essential element in any IDE, and should be mandatory inclusion, since it is essential to know the characteristics of the information with which to work. The international standard governing the metadata is ISO 19115 "Geographic Information Metadata." In Spain we also have Spanish Metadata Core (NEM), which constitute a recommendation or profile, which shows the minimum requirements to meet the geographic information metadata.