Newbie (what the values means)

Hello, sorry for my newbie question but i want to start playing with motion sensors. What the value means for the device ?

for acceleration

if the raw data output is

first instance
ax= 100
ay = 0
az= 0

second instance
ax= 400
ay =0
az = 0

third instance

ax= 0
ay =0
az = 0

for gyroscope

first instance
gx= 10
gy= 0
gz= 0

second instance
gx= 40
gy= 0
gz = 0