A definition of strength and conditioning can be the repeated application of force against various forms of resistance.
Strength applies “conceptionally” to force production whereas conditioning applies to the application of movement (e.g. through speed, agility and quickness).
During conditioning the primary resistance is body weight.
Sometimes you use e.g. medicine balls (MB) but the resistance needs to be low because you don’t want the resistance to cause deviation to the form of the movement and velocity.
Strength can be defined as the application of high force against a heavy resistance whereas conditioning is the repeated application of force against a resistance.
When you run, for instance, weight vests heavier than 20lbs shouldn’t be used because they would slow the athlete down too much.
Also, the velocity-based (plyometric) MB throws do not exceed 8-10 lbs.
When you engage in strength applications (ballistics) with MB then they weigh up to 25lbs.
So, during conditioning you aim at higher speed movement and challenging the metabolic system.
On the other hand, during strength applications the focus is on high force neural challenges with some metabolic conditioning.
During conditioning emphasis is on pushing the glycolytic pathways.