What is the difference between a turtle and a tortoise?

A turtle is aquatic, needs water to feed and breed.
Turtles are also carnivorous for the most part, feeding on insects, worms small fish, snails etc. and some, like the sanpping turtles on larger prey.

A tortise is a land animal, wet conditions rot their shell. They need warm dry conditions and are vegetarians.

Yep, what @Coloma said. Tortoises stick to land and turtles are often amphibious.

@Coloma, I don’t think that’s correct.

Turtles can be either land or water animals. Tortoises are turtles that live only on land.

In other words, turtles are the general order of reptiles with an armored shell. Tortoises are the land-based family within that order.

Whatever the scientific difference, I grew up using the term turtle for all shelled tortoise-like reptiles.