"Significant Motion sensor" same as accelerometer? I am trying to understand better the "Significant Motion" sensor:

I know that I have accelerometer. Does it mean that the device also supports "Significant Motion sensor"?
According to https://source.android.com/devices/sensors/sensor-types.html#significant_motion it is the same, but I'm not sure.

Is there a utility/apk to check its validity ?

Thank you,
Ran
The significant motion sensor is a virtual sensor using the physical accelerometer. From android.com: 


  A significant motion detector triggers when the detecting a “significant motion”: a motion that might lead to a change in the user location.


This means the significant motion sensor will only provide data if a significant motion is detected by the system (e.g. walking). The accelerometer continuously returns the accelerations for each axis.

To check out those sensors you can install one of many sensor apps. I usually use cpu-z.