1. Accuracy and Precision
Data Analysis Terminology

2. Accuracy is about how close your measured value is to the accepted value. (accepted is defined by the discipline) High accuracy is about getting really close or getting the correct value. Low accuracy is when your value is no where near the correct value.

3. Precision is about getting the same or nearly same result each time
Precision is about getting the same or nearly same result each time. High precision is getting almost the same number each time. Low precision is getting very different numbers each time.