ArcGIS applications include a Catalog window that is used to organize and manage various types of geographic information as logical collections—for example, the data, maps, and results of your current GIS project that you work with in ArcGIS.
The Catalog window provides tools to accomplish the following:
- Browse and find geographic datasets to add to your map.
- Record, view, and manage datasets and ArcGIS documents.
- Search for and discover GIS data on local networks and the web.
- Define, export, and import geodatabase data models and datasets.
- Create and manage the schemas of geodatabases.
- Add connection to and administer ArcSDE geodatabases.
- Add connection to and administer ArcGIS Online (My Hosted Services).
You can work with the Catalog window in ArcMap, ArcGlobe, and ArcScene.
Working with the tree view in the Catalog window
Using the tree view in the Catalog window is much like using Windows Explorer, except the Catalog window focuses on viewing and working with GIS information. It shows you a list of folder connections, geodatabases, and GIS services. You can use the Location control as well as the tree view to navigate to workspace folders and geodatabases.
In the Catalog window, you'll see your GIS contents organized in a tree view series of nodes—for the map's Home folder, other folder connections containing GIS contents you frequently use, and other types of ArcGIS connections. 
The panel underneath the tree view displays contents and properties of the item highlighted in the tree view. In the tree view, you can do the following:
- Click an item to preview its properties.
- Select items and drag them into ArcMap, geoprocessing models, and other dialog boxes.
- Review and update items and their descriptions.
- Perform various operations on each item by right-clicking the item to see its context menu.
Using the stand-alone ArcCatalog application as an alternative to the Catalog window
In addition to the Catalog window in ArcMap, ArcGlobe, and ArcScene, there is a stand-alone application named ArcCatalog that can be used as an alternative for managing workspaces, geodatabases, GIS web services, and ArcGIS Online. ArcCatalog is used by administrators to manage their ArcGIS information. For example, administrators often use ArcCatalog to manage ArcSDE geodatabases and deployments of ArcGIS for Server because they do not need a corresponding map session.
In addition, many use ArcCatalog to manage their standards-based metadata for item descriptions. See Working with standards-based metadata for more information.