Error is the difference between the true value of a quantity and the measured value of that quantity. In analytical chemistry, errors can be classified into two types: systematic errors and random errors.
This is caused by the improper analytical method or by malfunctioning in the instrument.
If a balance is always reading 10 grams too high, this is a systematic error that can be corrected by subtracting 10 grams from all of the measurements made with that balance.
Random errors, also known as indeterminate errors, are occur due to variable methods or due to the limitations of instruments.
If a balance is not perfectly calibrated, this will introduce errors into the measurements.
Accuracy refers to how close a measured value is to the true or accepted value. It quantifies the degree of correctness or the absence of systematic measurement errors. Accuracy is determined by comparing the measured value to a reference value or a known standard.
Precision refers to the degree of consistency, reproducibility, or exactness of multiple measurements of the same quantity. It quantifies the level of random errors or variations in measurement.