Biology is the science that studies living things: how they work, how they grow, how they interact with each other, and how they've changed over millions of years.

Biologists investigate everything from the tiniest bacteria that live in your gut to massive blue whales swimming in the ocean. They examine how a sunflower turns its face toward the sun, how your body fights off a cold, why some butterflies migrate thousands of miles, and how traits pass from parents to children. Biology explores what makes something alive in the first place: the ability to grow, reproduce, respond to the environment, and use energy.

The field divides into many specialties. Marine biologists study ocean life. Microbiologists examine organisms too small to see without a microscope. Botanists focus on plants, while zoologists study animals. Ecologists investigate how living things interact with their environments and with each other.

Biology connects to almost everything in your daily life. When doctors develop new medicines, when farmers breed stronger crops, when conservationists protect endangered species, or when you simply wonder why dogs pant when they're hot, that's biology at work. Understanding biology helps us make sense of the living world around us and our place in it.