The following section explains the platform basics and fitness data formats and terminologies used by the Google Fit platform.
Data sources represent unique sources of sensor data. They can expose raw data coming from hardware sensors on local or companion devices, which is categorized as TYPE_RAW. Data sources also expose derived data, created by transforming or merging other data sources, which are categorized as TYPE_DERIVED. They hold the metadata regarding the source, such as which hardware device (device name) or application (package name) generated the data. Multiple data sources can exist for the same data type, for example for the heart rate data type, we can have a heart rate sensor in a watch and a heart rate sensor in a chest wrap that show as two different data sources for one data type.
