Tortoises and turtles both have very different habitats. While tortoises are terrestrial, including even some semi-aquatic species that live closer to various types of body of water such as ponds, most turtles are considered to be aquatic, in nature. Among these species, you will find the sea turtles.
The second difference between tortoises and turtles is focusing on their legs. Tortoises have short, stubby feet while true turtles such as sea turtles, have flippers. Of course, some species of tortoises and turtles are considered semi-aquatic and have webbed feet. Such feet allow them to walk on land and swim easily in water.
The third difference is speed. Due to their cumbersome shell, tortoises are known to be much slower than turtles. After all, they walk on land while their aquatic cousins may be slow on the sand but much faster in water as they are excellent swimmers.
The fourth difference is the shell. Tortoises carry a heavy dome-shaped shell, to the exception of the African Pancake tortoise which has a flat carapace. The scales on the shell of a tortoise have a rougher texture and are much tougher. A turtle's carapace, on the other hand, is smoother and usually flat.
The fifth and last difference is the molting phenomenon. Like snakes both tortoises and turtles molt their skin. Molting is a process during which, tortoises and turtles shed their skin. Although they do not do it in one time, it is still something they are periodically going through. While the scales on a turtle are smoother and smaller on the new skin, the dead skin is falling off. Contrary to turtles, tortoises the dead skin is not falling off. In fact, it is accumulating in thick knobs and plates, adding protection from predators.
Despite common beliefs, there are some differences between tortoises and turtles. Next time you go to the zoo or see a documentary on reptiles, try to spot tortoises and turtles. You have now all the knowledge to be able to easily identify and differentiate them. Are you up to the challenge?
Here are some resources linked to turtles and tortoises.