The validity or reliability of a study is a measure of an experiment or studies that helps in to check or test if a study is correct or not. It helps in the determination of the study method and explanation of the phenomena of particular study.
The reliability or validity of a study can be established by same results or conclusions by repeating the study or experiment every time.
In Nature's rule of law; it is technically both. The only difference between the two would be photosynthesis happens with plants. While cellular respiration happens with living beings.
