A measurement result is considered accurate if it is judged to be close to the true value. Accuracy is how close to the true value a reading is; precision is a measure of reproducibility – how close together your results are – how much random variation they have; resolution is the smallest change detectable with your equipment . Be careful not to confuse accuracy, precision and resolution.
Once you’ve watched this video take another look a the diagram on the glossary – it should start to make a lot more sense.
A LOT more technical than the video above but the information could be useful for longer and more difficult questions regarding practical results. Just ignore the reference to OCR GCSE – the content of this video is is appropriate for all science GCSE’s or A levels