These are the definitions of reliability and precision that I have. Precision is how the data you've collected in an experiment matches up with each other, you know how you do an experiment more than once? It's how well they match. This is like an official definition; Precision refers to how well experimental data and values agree with each other in multiple tests.
Reliability is like whether the experiment has been repeated or not. Always put repetition if if asks for something like "How could you improve the reliability of this experiment?" Also depending on the experiment it reliability can be improved through a large sample size.
Hope this helps.