Geocoding is the process of transforming location information (e.g., street addresses, place names, etc.) into geocoordinate data (e.g., latitude/longitude) that can be plotted and symbolized on a map.
Reverse geocoding is the process of taking latitude and longitude values from a map layer and converting them into street addresses or place names.
There are a number of browser-based geocoding tools that can be used if your research project doesn't include sensitive data (e.g., HIPAA, personally-identifiable data, etc.) If you are working with sensitive data, we recommend that your create your own address locator to run within a secure environment.