A viewbox, also known as a bounding box, is a rectangular area used to define a geographic region for a geocoding API. It is typically defined by the coordinates of two opposite corners of the rectangle (i.e. the northwest and southeast corners). The viewbox can be used to limit the search area or results of a geocoding query, allowing for more precise and relevant results.
For example, let's say you have a business that delivers goods within a specific city. You can use the geocoding API to find the coordinates of the city's center, then use the coordinates to define the viewbox that limits the search area to the city's boundaries. This will prevent the geocoding API from returning results outside of the city, ensuring that the results are relevant to your business.