While arguments attempt to show that something is, will be, or should be the case, explanations try to show "why" or "how" something is or will be. If Fred and Joe address the issue of "whether" or not Fred's cat has fleas, Joe may state: "Fred, your cat has fleas. Observe the cat is scratching right now." Joe has made an "argument that" the cat has fleas. However, if Fred and Joe agree on the fact that the cat has fleas, they may further question "why" this is so and put forth an "explanation": "The reason the cat has fleas is that the weather has been damp." The difference is that the attempt is not to settle whether or not some claim is true, but to show "why" it is true.