GMSMapStyle
holds details about a style which can be applied to a map.
With style options you can customize the presentation of the standard Google map styles, changing the visual display of features like roads, parks, and other points of interest. As well as changing the style of these features, you can also hide features entirely. This means that you can emphasize particular components of the map or make the map complement the content of your app.
For more information see:
https://developers.google.com/maps/documentation/ios-sdk/styling