You have several options for customizing Google Maps Platform (GMP) maps. Most of these methods require you to use a map ID to access several different map customization features. You can also manually customize GMP maps using JSON styling,
Customize maps with map IDs
A map ID is a unique identifier that represents a single instance of a Google Map. Map IDs are restricted to a single platform–JavaScript, Android, iOS, or Static maps. You associate map IDs with a project, and can use map IDs to enable features or manage or style maps on your websites and in your applications. For details, see Map ID overview.
Customize with map IDs and Cloud-based maps styling
With cloud-based maps styling, you use map IDs and map styles to create a customized road map experience for your users. You can then update the style as needed in the Cloud console, without having to update your apps' code. For details, see Cloud-based maps styling.
Customize maps manually with JSON styling
Manually customizing maps lets you style the normal map type, and does not require a map ID. Any updates to the style require a code update. You cannot combine manual map styling and cloud-based maps styling in the same app.
To customize a map manually using JSON styling, see JSON map styling.