Existing vector data may be the initial input for the geodatabase. Many kinds of vector data can be used as input, including coverage, shapefile, computer-aided design (CAD), or geodatabase data. Before the data can become usable, it must have a defined projection.
Projecting
If your data has a defined projection that is different from the feature dataset, the data loader in ArcCatalog automatically projects the data on import. If the data does not have a defined projection, the coordinate system information can be defined within ArcMap; otherwise, it may be necessary to project the data before importing. Project the data by changing the projection of the data frame to the desired projection and export the layer using the data frame properties.
In some cases, the data may not be in a useful coordinate space, such as scanner or digitizer units, which most often are inches or microns. Provided the data has some reference points, such as known locations of road intersections or ticks that represent x- and y-coordinates, the data can be transformed into real-world coordinates with the spatial adjustment tools.
Loading geodatabase, coverage, and shapefile data
The ArcGIS Desktop Load Data tool that is available in ArcMap can be used to import data into a specific feature class. As part of the load, a query can be applied to load specific data from the source dataset. Data may be loaded into a specific subtype and attribute fields can be remapped; however, only one feature class can be loaded at a time.