The difference between planning and scheduling is$$

The information from scheduling is fed into planning

Scheduling is a tool while planning is a process

There is no difference

Schedule and Planning go hand in hand

Both $2$ and $3$

Both $2$ and $4$

Backward pass determines the latest start and the latest finish

Forward pass calculations yield the earliest and the latest start and finish times of various activities

Determination of the earliest and the latest start time of various activities of a project is useful for proper planning of their execution.