What is a Gazetteer?
A gazetteer is a geographical list or dictionary of place names. There are three types of gazetteers: alphabetical list, dictionary, and encyclopedic. Gazetteers are useful resources if you're trying to find historical names for places (e.g., countries, regions, streets, etc.), alternate names, etc.
Gazetteers can be used to identify XY coordinates (e.g. latitude / longitude) for places / geographic features, which can be useful if you want to plot the locations on a map.