It's a quote that originated as a paraphrase of Einstein about applying Occam's razor to development of scientific theories. Things should be as simple as poss

It's a quote that originated as a paraphrase of Einstein about applying Occam's razor to development of scientific theories. Things should be as simple as possible, with respect to your criteria. E.g. a scientific theory should posit as few objects as possible while still being able to explain all observed phenomenons.