Why it matters.

It offers a different way to describe surface shape and texture.

A closer look.

A larger apparent source gives softer edges. Bringing a large modifier closer can increase its apparent size; moving it farther away makes it relatively smaller.

Picture this

Compare a small lamp with a broad window from the same side of an object.

Keep in mind.

Soft light can still be directional and create shadows. It does not automatically remove contrast.