Each layer references a dataset that is stored in a geodatabase, coverage, shapefile, raster, and so on. It's easy to add layers to a map—you simply select a dataset and drag it from the Catalog or Search window onto your map or add a dataset using the Add Data button.
Once each layer is added to your map, you'll typically set the symbology and labeling properties and organize the drawing order of the layers in your table of contents to make your map work well.
If your data is stored in a format supported by ArcMap, you can add it directly to your map as a layer. If your data isn't stored in a supported format, you can use the data conversion utilities in ArcToolbox or the Data Interoperability extension to convert practically any data and display it in your map.
Adding map layers
There are a number of ways to add map layers. Each of them is covered here.
Adding a dataset
To create a new map layer, simply add a dataset to your map, globe, or 3D scene. There are a few ways to add datasets:
- Using the Add Data button—Click the Add Data button
and navigate to the desired dataset. Then select and add it to your map.
- Copying or dragging a layer—You can move layers between data frames or maps by copying and pasting or dragging the layer from one data frame to another.
- Dragging a dataset from the Catalog window—You can navigate to datasets and add them directly in ArcMap. Using the Catalog window, navigate to the desired dataset. Drag the dataset into the map's data frame.
- Dragging a dataset from the Search window—You can add data to your map from the Search window. Click Data, enter the search terms to find the desired dataset, then drag the dataset into the map's data frame.
See Using search in ArcGIS for more information.
- Dragging a dataset from ArcCatalog—You can add data to your map from the ArcCatalog application. In ArcCatalog, navigate to the desired dataset. Then drag it onto the ArcMap data frame.
Adding multiple datasets—You can select and add multiple datasets at one time by highlighting all of the desired datasets instead of a single one when adding.
Adding data from ArcGIS Online
You can add data and layers that are published and shared online by the ArcGIS community. See Adding data from ArcGIS online for more information.
Setting layer symbology
When you create a new layer by adding a dataset, the layer will be drawn using a default set of drawing properties. So one of your first steps will be to set the layer's symbology and other display properties.
See About displaying layers for more information.
Setting the layer drawing order
When adding a new layer, it will automatically be placed above others of the same type. For example, a new line feature will be placed above other line features. Thus, you'll want to position layers appropriately. For example, you may want to place layers that form the background of your map, such as an ocean layer, at or near the bottom of the table of contents.
The default layer drawing order—If you simultaneously add a number of datasets to your map, the new layers in your map will be ordered as follows (raster on the bottom):
- Annotation
- Features
- Point
- Line
- Polygon
- TIN/Terrain
- Raster
For more information, see Listing by drawing order.
Common layer operations
Once a layer is part of a map, you can do all of the following:
- Toggle the layer display on and off.
- Move layers from one data frame to another.
- Set scale-dependent drawing for your layer.
- Choose which features or subset of features to display.
- Set layer properties and symbolize the layer.
- Label the layer.
- Save layers and layer packages for sharing.
- Display and work with tabular information about a layer.
- Organize a logical collection of layers into a group layer for various purposes.
- Add the layer to a basemap layer for increased display performance.
When layers aren't being drawn on the map
When layers are turned on but are not being drawn on the map, the table of contents may provide some clues. In the table of contents below, all the layers are checked on for display, but the parks and lakes layers do not appear in the map display.
In the example below, the parks layer is not drawing because the link to its data source is broken, indicated by the red exclamation point (!) beside the check box. The lakes layer is not drawing because the current display map scale of the data frame is outside the layer's visible scale range, indicated by the dimmed scale bar under the check box.
See repairing broken data links and displaying layers at certain scales for more information.
Removing layers from a map
When you no longer need a layer on your map, you can remove it. Select the layer, right-click, and choose Remove.
Removing a layer doesn't affect the underlying data source on which the layer is based. You can delete (and manage) data sources, such as a feature class, using the Catalog window.
Adding layers to a map from Windows, e-mails, or Web pages
Layer files and layer packages are registered to the ArcGIS for Desktop applications, allowing you to double-click them in Windows Explorer, Microsoft Outlook, the Windows Desktop, and so on, and add them directly to your current ArcMap or ArcGlobe session. Layer files will appear with the familiar yellow icon. Clicking layer files embedded in Web pages will also add them into your session.
If you don't have an ArcGIS for Desktop application running, opening a layer file will automatically start the appropriate application: ArcMap will start and add the layer into the empty map, or in the case of layer files containing 3D-only content, ArcGlobe will start and add the layer into the globe.