Sensor.info vs. Activity.getActivityInfo

For activity.recordings / session creation and usage of Sensors (eg: GPS/HR/Footpod) etc

in the API, I see 2 different pages and in some cases, duplicate (?) readings. Or perhaps it's just me being confused.

Sensor-Info
http://developer.garmin.com/downloads/connect-iq/monkey-c/doc/Toybox/Sensor/Info.html

Activity-Info
http://developer.garmin.com/downloads/connect-iq/monkey-c/doc/Toybox/Activity/Info.html


eg: For HR
if( sensor_info.heartRate != null ) { HR = sensor_info.heartRate.format("%d");}
http://developer.garmin.com/downloads/connect-iq/monkey-c/doc/Toybox/Sensor/Info.html#heartRate-instance_method

if( Act.getActivityInfo().currentHeartRate != null ) { HR = Act.getActivityInfo().currentHeartRate.format("%d")
http://developer.garmin.com/downloads/connect-iq/monkey-c/doc/Toybox/Activity/Info.html#currentHeartRate-instance_method

Both of them seems to provide the same (?) data set.

Which should I use?
Or.... is the sensor one for external sensors and the other one, getActivityInfo() are all Internal sensors?