In many ways there are no differences. I am not a scientist, but an interested and informed 'layman'. We should make some distinctions among different kinds of 'knowledge'.
At one time in history,...
A scientific theory has a different definition from a "general" theory of everyday use. "Regular" theory (according to dictionary.com): contemplation or speculation.guess or conjecture. Scientific...
scientific law: a statement or equation that can predict what will happen in certain situationsscientific theory: a scientific explanation that connects and explains many observations