Terrapins are one of several species of small turtle living in fresh or brackish water. They are not a taxonomic unit and may not be closely related. Many belong to the families Geoemydidae and Emydidae. The name "terrapin" is derived from torope, a word in an Algonquian language that referred to the species Malaclemys terrapin (the Diamondback terrapin). The exact name used for a particular type of turtle can vary depending on where they live or where you live. However, in general, there are a few commonly accepted distinctions between turtles, tortoises, and terrapins.

Here are some key differences between turtles, tortoises, and terrapins:

• Turtles: Turtles are marine reptiles that live in the ocean. They have flippers and streamlined shells to help them swim.

• Tortoises: Tortoises are land-dwelling reptiles that spend most of their time on land, eating shrubs and grasses. They dont have webbed feet since they dont spend much time in the water.

• Terrapins: Terrapins are semi-aquatic, freshwater-living turtles that spend time both on land and in brackish, swampy water. They tend to swim quite often but also spend their time on land, basking in the sun and occasionally burrowing in the mud. They have legs similar to tortoises and a slightly streamlined yet also slightly domed shell.

In the UK, the word "terrapin" is used to describe those chelonians living in freshwater, while the word "turtle" is reserved for those in marine environments.