Passing in basketball has been defined as "The deliberate attempt to move a live ball between two teammates",[1] a definition which might equally apply across other sports equally well, albeit with a change to the item being passed where appropriate.
In certain sports, a pass to a teammate that leads to a successful scoring move is recorded, and tracked.
[2] A team with a high number of assists demonstrates effective ball (or puck) passing between teammates, which is critical in most team sports, as it tends to lead to more, and higher quality scoring opportunities.
Assists are also tracked in baseball, and any defender that touches a fairly hit ball that leads to a putout is credited.
Similarly, they may not have been intentional passes (as opposed to fortuitously trying to move a ball upfield to gain possession).