Difference between accelerometer and gravity sensor

Accelerometer and the gravity censor basically does the same thing but the intensity and precision changes....
Accelerometer is actually the thing which aids us to play games having a virtual experience and has a relatively high precision in detecting our motion(acceleration)....
Gravity sensor just recognises the way your phone, usually a smartphone, is oriented in the plane. Just when u flip flop a phone the screen also flip flops.....