Key Difference: If the mixture can be kneaded into a shape, it is often a dough and if it can’t, most likely it is a batter.

See the difference Corn flour Vs. Cornstarch.

To the horror of bakers and chefs everywhere, the terms dough and batter are often used interchangeably. Most of the time, the terms are used by the tongue, which basically means that people use the term because it has been used that way for so long but they don’t know the reason behind this.

So, people have always referred to cake batter or bread dough, but they don’t know why they are known as dough or batter. The reason for it is quite simple actually. According to numerous experts (i.e. chefs and bakers), the difference between them has to do with liquid content. Higher liquid content means batter, while less liquid content means dough.
See the difference Oat Vs. Wheat.

A rule of thumb is usually if the mixture can be kneaded into a shape, it is often a dough and if it can’t, most likely it is a batter.

Some experts have even come up with a liquid to flour ratio to create a clearer distinction between dough and batter. If the liquid to flour ratio is 1:1 or 1:2, which means 1 part water to every 1 part flour or 2 parts flour, it is batter. If the liquid to flour ratio is 1:3 or 1:4, it is dough. However, there are certain exceptions to this rule which includes macaroons or candy corn. These often lie somewhere in between.

The dough is most commonly used to make bread, pastries, rotis and naan (flat bread). While, batters are used to create cakes, pastries, cupcakes, omelets, and even for coating (such as washes). See the difference Multi grain Vs. Whole grain Vs. Whole wheat. 

A fun fact about the term batter is it gets its name from the actual mean of batter which is being beaten. If you notice, when creating a batter you usually beat it with the spoon or a whisk or even a blender. Hence, it is referred to as a batter.

Difference between Dough and Batter:

Image Courtesy: abenzymes.com, simplyscratch.com