There are a lot of people who think that the groundnut is the same as peanut. In fact, some people would think that these are synonyms. Peanut is very precise and you will immediately know what it is referring to. Peanuts can be served in a lot of ways.
Some would like them boiled while others would love them fried. Peanuts are usually considered as snacks in various parts of the world. Groundnut, on the other hand, is known as a food plant.
When you say groundnut, this means that this refers to something that is far wider than peanuts. There are other nuts that can be considered as part of groundnuts.