* Free-fall refers to the motion of an object solely under the influence of gravity. This means no other forces are acting on it, like air resistance.

* Projectile motion describes the path of an object launched into the air with an initial velocity. It includes the effects of gravity but also potentially other forces like air resistance.

Here's a breakdown:

* Free-fall: A skydiver falling after deploying their parachute (ignoring air resistance) is in free-fall.

* Projectile motion: A ball thrown across a field is a projectile. It experiences gravity, causing it to arc downwards, but also air resistance, which slows it down.

In summary:

* All free-falling objects are projectiles, but not all projectiles are in free-fall.

* The key distinction is the presence or absence of forces other than gravity.