Chemistry, What is the diffrence between Precision and Accuracy?

Precision is the ability to reproduce the result. Accuracy is having the "correct" answer. For example, if you throw five darts and they all miss the board by many feet, but all land in the same spot (say, all in same part of the floor), then the darts are precise, but not accurate. If you throw the darts and they all land on different parts of the board, but not all together, they are fairly accurate, but not precise. Precision is about getting the same result each time, regardless of how right the answer is. Accuracy is getting values close to the accepted value (the correct value), but does not require each answer to be close to one another. In chemistry, being accurate is not enough. Results must be repeatable, must be precise, in order to prove that a pattern exists. Getting the right answer once does not prove a concept.