Algae are a type of living thing that usually live in really wet environments, like the ocean. They are a little bit like plants. They take energy from the sun and use it to make food, just like plants do! The difference between algae and plants, is that plants have a lot more distinct parts, like roots, petals, stems, and leaves. In this way, algae are a lot simpler. They tend to just have one body part. It could look like a leaf, like moss, or like slime!
You're probably familiar with some algae and don't even know it! One very common type is found at the beach: seaweed.
Algae come in a big variety of shapes and sizes, from specs, so tiny that you need a microscope to see them, to giant kelp, which is seaweed that can grow to over 200 feet long!