Static friction is the force that prevents the relative motion between two objects that are in contact but not sliding past each other. On the other hand, kinetic friction comes into play when the two objects are already in motion relative to each other. The transition between static friction and kinetic friction occurs when the applied force exceeds the maximum static friction force.
When you try to push or move an object, you initially apply a force smaller than or equal to the maximum static friction force. In this case, the object remains stationary, and static friction opposes your applied force. However, if you gradually increase the force, reaching a point where it equals the maximum static friction force, the object is on the verge of moving but hasn't started moving yet.
Once the applied force exceeds the maximum static friction force, the object starts to move, and static friction is no longer in effect. At this point, kinetic friction takes over, opposing the relative motion between the two objects. Kinetic friction is typically slightly smaller than the maximum static friction force.
In summary, static friction prevents motion between objects up to a certain threshold, and kinetic friction comes into play once the applied force exceeds that threshold, causing the objects to move relative to each other.