Grappling is a generic term referring to either the act of "ground sparring" or as a layman's term for any style that focuses on wrestling, submissions, or juijitsu.
As a shoot stylist I mostly agree with MaddenHB. Shootfighters has a slightly different philosophy than wrestlers and juijitsu stylists. Shootfighters incorporate a variety of techniques in their training as we use striking in combination with submission wrestling. Generally, wrestlers tend to have better control and balance on the ground. Also, juijitsu stylists tend to be far more technical and fluent with submissions. Shootfighters, however, usually have an overall better "game". Shootfighters are proficient strikers, wrestlers, and submission grapplers. Also, unlike juijitsu practicioners, shootfighters emphasize submission over position. And yes, it's true, we are leglock specialists.