Use the Spatial Join tool to determine the geographic areas that each point in their point data falls within (e.g., which Census tract or block group each is in, which police precinct each is in, which school attendence zone each is in). This allows associating, with each point, data that is aggregated by such polygon features (the geographic identifier, such as the name of the Census tract, for example, and any other variables in that layer's attribute data).
You might also want to associate attributes of nearby line or point features in another layer.
This can be done using a Spatial Join, which associates all the attributes of a join feature (e.g., a polygon) to each of the target features (e.g., each point) that is within it.
Also see another page in this guide regarding the Spatial Join.
ArcGIS can determine the location of addresses, for instance if you have a spreadsheet with address data. You need to have a steet layer formatted appropriately. ArcGIS will create a point at the location of each address. Clean data is essential.
Three ways of getting an address locator:
Online help. You can plot your data that has coordinate information (latitude/longitude or any other coordinate system) into ArcGIS. The program plots the locations as points on your map.
You can open the table with the XY coordinates, then right-click on it in the Contents Pane in order to open the Make XY Event Layer tool.
COORDINATE SYSTEM (VERY IMPORTANT): In the Add XY dialog box, look at the coordinate system that ArcGIS is assuming your data is in before you click through to create your points.
The default will be whatever your data frame is already in. For instance, if your data frame uses NAD83 State Plane North Carolina Feet, then ArcGIS assumes your tabular coordinates are in feet, not degrees. If these are really Longitude (X) and Latitude (Y) coordinates in degrees, you must change your coordinate system to unprojected (geographic) coordinates, typically WGS84 (the last choice under Geographic...World).
Making a permanent GIS layer: The plotted points in the XY Event layer are just pointing back to your tabular data; they don't represent a new layer. If you then need to use tools on the point layer, such as a Spatial Join, then you will first need to export it as a feature class (e.g., shapefile).
The output point feature layer created by this tool is temporary and will not persist after the session ends. You can export this event layer to a feature class (geodatabase layer or shapefile) by right clicking the layer's name in the Contents Pane, then Data ... Export. this opens the Copy Features geoprocessing tool. You can also use the Feature to Point or Feature Class to Feature Class tools.