Starting point and Source

Starting point noun - Earliest limiting point.

Source is a synonym for starting point in origin topic. In some cases you can use "Source" instead a noun phrase "Starting point", when it comes to topics like base, beginning, start of an event or action.

Source noun - A point or place at which something is invented or provided.

Starting point is a synonym for source in beginning topic. You can use "Starting point" instead a noun "Source".