* Mixture: A mixture is a combination of two or more substances that are not chemically bonded. They can be separated by physical means.

* Compound: A compound is formed when two or more elements chemically combine in a fixed ratio.

Groundnut oil is extracted from peanuts and is primarily composed of triglycerides, which are large molecules made up of glycerol and fatty acids. These triglycerides are not simply mixed together, they are chemically bonded and form a single, uniform substance.

Therefore, groundnut oil is a pure substance, specifically a lipid (fat).