Algae are simple, plant-like organisms that can be found in water, both freshwater and saltwater. They come in various shapes and sizes, from tiny phytoplankton to large seaweeds. Algae play a crucial role in the ecosystem by producing oxygen through photosynthesis and serving as a food source for many aquatic animals, such as fish and zooplankton. There are many types of algae, including green algae, red algae, and brown algae, each with unique characteristics. Some algae can even be found on land in moist environments. Scientists study algae for their potential uses in food, biofuels, and even medicine, highlighting their importance beyond just being part of aquatic life.