> For the complete documentation index, see [llms.txt](https://guides.mapaction.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guides.mapaction.org/gis-and-information-managment/layers-of-data.md).

# Layers of data

A map is made up of different layers data, each showing new information that gives additional context to the layer above. In a humanitarian context these layers can be grouped into three data categories.

<figure><img src="/files/cfkNS5G1p74jRW3ikXLf" alt=""><figcaption><p>Layers of data</p></figcaption></figure>

### Basemap

This is geographic data that is used as background mapping. Some form of basemap data is needed for every map. Examples of basemap data include:

* administrative boundaries
* settlements
* transport
* physical
* elevation

### Baseline

This is typically demographic data about the country or area of interest (AOI) before an emergency. This data allows you to compare situational data against ‘normal’ conditions. Examples of baseline data include:

* number of schools
* health facilities
* election results
* population

### Situational

This is data for the country or area of interest (AOI) produced after the emergency. It is the most important data that you are trying to show on the map. Situational data has some currency to it and some of it may become baseline data over time. Examples of situational data include:

* number of internally displaced people (IDPs)
* infrastructure damage
* earthquake epicentre
* flood extents
* road status


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