This refers to the number of steps and rough distance while you are walking while wearing the device.
Meter
Distance (calculated value)- This refers to rough distance travelled converted from the number of steps counted with the acceleration meter and your height.
- Accumulated number of steps for the day
Target
This refers to the target number of steps per day as the goal.
You can change the target number of steps in [Settings] - [Goal Settings].
Graph
One day
- This refers to the change in number of steps by hour for the day.
One week
- This refers to the change in the number of steps for the week.
This also shows the relationship with the Target line and the maximum number of steps for the day. 
One month
- This refers to the change in the number of steps for the month.
This also shows the relationship with the Target line and the maximum number of steps for the day. 
Target Line
- This refers to the target number of steps for the day.
You can change this value from [Settings] - [Goal Settings]. 