The Manage Data toolset contains tools for both the day-to-day management of geographic data and for combining and overlaying data as part of spatial analysis
Finds polygons that overlap or share a common boundary and merges them together to form a single polygon.
Copies all features from two layers into a new layer. The layers to be combined must contain the same feature types (points, lines, or polygons). You can control how the fields from the input layers are joined and copied.
Overlays the geometries from multiple layers into one single layer. Overlay can be used to combine, erase, modify, or update spatial features. Overlay is much more than a merging of geometries; all the attributes of the features taking part in the overlay are carried through to the result.