Ecology is a science. It belongs to biology, the science of life. The Greek word “eco” means “house” or “household”. It’s about the coexistence of people with their things. Ecology is about how animals and plants live together. Every living being is also important to other living beings, and they also change the environment in which they live.
An ecologist is a scientist who studies a stream, for example. A forest, a meadow, or a stream is called an ecosystem: Fish, toads, insects and other animals live in the water of the stream. There are plants there too. You can also see creatures on the shore. For example, the ecologist wants to find out how many fish and insects there are, and whether many insects mean that many fish are alive because they find more food.
When they hear the word ecology, many people only think of the environment, which can be polluted. For them, the word means something similar to environmental protection. Often you just say “eco”. An “eco-detergent” is said to be not that bad for the environment. A green party is sometimes called an “eco-party”.