Grappling is inherently ‘sticky’. You grab your opponent and do not let go. Boxing, on the other hand, is the opposite of sticky. In the cases when boxers grab hold of each other and clinch, the referee will break them apart.
The separate goals are obvious in these contexts. Boxing is striking at a distance. Grappling and wrestling are about close-in controls.
Many perceive Wing Chun to be like Boxing, as it employs strikes and kicks. However, Wing Chun is more akin to Grappling. The goal in Wing Chun is to gain control. The second part of the Kuen Kuit, the Fight Philosophy, is to stick to an attack or the attacker as it retreats, to collapse the assailant and their weapons to gain control over them. Strikes are used as a means of gaining contact in order to stick to the opponent.
Unlike the strikes in Boxing, where the goal is to knock the opponent back, the strikes in Wing Chun are designed to get close, and closer. Wing Chun is very sticky.