What is the difference between precision and accuracy? Doesn't they imply to the same meaning?
What is the difference between precision and accuracy? Doesn't they imply to the same meaning?

No.
Precision is the smallest amount, or resolution, to which you can measure, and how repeatable that measurement is. If you have a rule marked in centimetres, then your measurement will be precise to the nearest centimetre (subject to rounding up or down). If you have a rule marked in millimetres, your measurement will be more precise.

Accuracy is how reliable or true your measure is to the standard measure.

If you stretch your rule by 25%, your measurements are still precise to the nearest centimetre, but they're nowhere near as accurate.

See http://en.wikipedia.org/wiki/Accuracy
Owain