Occam’s Razor is a heuristic (rule of thumb) used in many areas of science and philosophy. Credited to Franciscan friar William of Ockham; “entities must not be multiplied beyond necessity” is often reworded as “the simplest explanation is usually the right one”.
I like the way the medical community explains Occam’s Razor; “when you hear hoofbeats, think horses, not zebras.”
Occam’s Razor is not a scientific law, theory or rule. It is more of a reminder not to over complicate a problem. Not to consider more possible causes than necessary.
♦ This is a very simplified view of the overall implications of Occam’s Razor in the scientific world but it is a full and complete explanation of the heuristic itself.