The BodyThrust object applies (or exerts) a force relative to the part to which it is parented at a specific location. It behaves similar to a BodyForce, except that this object's force applies at a specific point (BodyThrust.Location), allowing you to exert a [torque] (rotational force). To apply a force dynamically so that a part maintains a constant angular velocity, use a BodyAngularVelocity instead. To apply a force dynamically so that a part maintains a constant orientation (angular position), use a BodyGyro.
The Force property determines the amount of force exerted on each axis relative to the part. Unlike BodyForce.Force, this property is relative to the part and not the world. The force is exerted at the Location, which is also relative to the part.