Terrapins and tortoises are actually relatively easy to distinguish, from the appearance, you can find their differences. The first is their feet. Terrapins generally have webbed feet and sharp toes because they need to swim, while tortoises are mainly on land, so their feet are not webbed, and because of friction, their nails are often bald. And their back is not the same, terrapin back is generally flat, and tortoises are mostly high back.
The main difference between terrapin and tortoise is habits. Terrapins can't live without water, and although they occasionally need to be raised dry, they still need to soak in water every day. If they are raised completely out of water, they will soon die of dehydration. Tortoises are mainly on land, so they don't need to soak in water, but many of them can swim. In addition, although turtles are omnivorous animals, terrapins often prefer to eat meat, while tortoises prefer to eat vegetarian food such as plants.
The distribution of terrapins and tortoises is also quite different. Terrapins must be near the water source. The reason has been mentioned above. This kind of animal cannot live out of water, so it is usually found in rivers and lakes. In addition to the distribution of tortoises in shrubs and tropical rainforests, there are also some species in dry grasslands and highlands, and only Australia does not have them, and many other continents can see them.