The first is saying that the two operations are complete opposites of each other. Photosynthesis turns CO2 into oxygen, and respiration turns oxygen into CO2. The second is saying that they have are related, which they are. The products of photosynthesis are the base components needed for respiration to happen.
I’m assuming the six kingdoms of life, but yes they do have a very large purpose for providing characteristics to bacteria, animals, fungi, humans, etc.
