Algae and phytoplankton are related but not the same. Phytoplankton are a type of algae that live in water and are microscopic. They are crucial for aquatic ecosystems because they produce oxygen and form the base of the food chain.
Algae, on the other hand, is a broader term that includes various types of photosynthetic organisms. These can range from microscopic single-celled organisms to large seaweeds. While all phytoplankton are algae, not all algae are phytoplankton.
In summary, phytoplankton are a specific group within the larger category of algae. They play a vital role in marine environments, while algae encompass a wider variety of organisms found in both aquatic and terrestrial habitats.