Final answer:
Rods and cones are photoreceptors in the retina with rods being sensitive to low light and responsible for night vision, and cones functioning in bright light for color vision and fine details.
Step-by-step explanation:
Since rods and cones respond to light, they are classified as sensory receptors called photoreceptors in the retina. Rods are effective in low light conditions and only detect shades of gray, which is why in dark environments humans mostly see in grayscale rather than in color. On the other hand, cones function in bright light and are responsible for our ability to see colors. There are approximately 120 million rods in the human retina dedicated to peripheral and night vision, while cones are primarily found in the central part of the retina and allow us to perceive fine details and color in well-lit conditions.