Although oil and butter can be used for similar purposes, they are not the same. Oil can be gotten from different sources such as nuts, seeds, fruits, and soya beans. The source of oil determines how healthy it is. Oil is most cases remain as liquid even at room temperature.
The oil contains unsaturated fat, which is considered healthier than saturated fat present in butter. Butter contains saturated fat, and it is gotten milk made by animals, most especially cows. At room temperature, butter is solid. When heated, butter foams in the pan. Butter also taste sweet compared to the neutral taste of the oil.
There are a lot of people who will agree that oil and butter can sometimes be used in similar situations yet they are also different. Oil can be extracted from different sources. There are some who may get oil from peanuts. There are some who may get oil from mustard seed and so much more.
This explains why you can see so many types of oil when you go to the market. Butter is usually extracted from milk which explains why butter usually has more calories as compared to oil. There are some types of oil that are considered to be healthier than others depending on where they were extracted.