A turtle is a reptile with a hard shell that protects its body. The shell is part of the turtle's skeleton, fused to its ribs and spine. When danger approaches, most turtles can pull their head and legs inside this protective armor.

Turtles live almost everywhere: oceans, rivers, lakes, deserts, and forests. Sea turtles swim thousands of miles across oceans, while box turtles might spend their entire lives in a single forest. Some turtles are tiny enough to fit in your hand, while leatherback sea turtles can weigh over 1,000 pounds.

People often confuse turtles with tortoises, but there's a helpful distinction: tortoises are land-dwelling turtles with stumpy, elephant-like legs built for walking on land. Turtles usually refers to species that live in or near water and have flatter, flipper-like feet for swimming. All tortoises are turtles, but not all turtles are tortoises.

Turtles move slowly on land, which is why we say someone is moving at a turtle's pace when they're going very slowly. But this slowness comes with an advantage: many turtle species live 50, 80, or even over 100 years. They've survived on Earth for more than 200 million years, outlasting many other animals.