How for residue and extract?

The terms "residue" and "extract" refer to different concepts in chemistry and various scientific fields. Residue typically refers to the leftover material remaining after a process, such as evaporation or filtration, while extract refers to a concentrated substance obtained from a source, often through methods like solvent extraction. For example, in herbal medicine, an extract might be made by soaking plant material in a solvent to draw out its beneficial compounds, leaving behind the residue of the plant material.