WHAT DOES 14 INCH 870 BARREL MEAN?

My Shockwave wears just one and it increased my successful range Using the gun out to 35 yards with Aguila mini slugs.  This was one a 21-inch tall popper, so I could most likely make effective hits out to 50 yards on a person-sized target.  The Smith and Wesson M&P Defend is usually a very popular and higher-need pistol. It's got a great sizing,