Ockham's Razor has two interpretations. One says that if you have several theories that might explain what you're observing, the simpler one is probably right.

Ockham's Razor has two interpretations. One says that if you have several theories that might explain what you're observing, the simpler one is probably right. It doesn't matter whether this is true; it saves time by letting you fail faster if you're wrong. This is the more popular understanding of the razor, but it's less useful because it can be wrong, and jackasses often use examples of its wrongness to claim that it never provides any information, in order to advance crackpot metaphysics or religion. The other says that if you have two theories which both explain everything you're observing, then it doesn't matter which one you adopt, so you might as well adopt the simpler one. For example, if I hypothesize that E=mc^2 + u, where u is the number of invisible, otherwise-undetectable pink unicorn particles within three meters of Mars, this theory makes all the same predictions as E=mc^2, and is nondisprovable. It's Occam's Razor that says that we shouldn't bother with this pink unicorn version.