title: What is the difference between "gravity" and "acceleration" sensors in Android?
body: <p>What is the difference between gravity and acceleration sensors in Android? From my point of view the physical value is the same in both cases.</p>
  
  <p>Which one measures the force acting on unit mass inside the device?</p>
  
  <p><strong>ADDITION</strong></p>
  
  <p>The question is: what physical quantity is measured by these sensors? According to <a href="http://en.wikipedia.org/wiki/Equivalence_principle" rel="noreferrer">equivalence principle</a> the acceleration and gravity are indistinguishable and the only way to measure both is by usual (but 3d) spring balance.</p>