At its simplest, biotechnology is technology based on biology - biotechnology harnesses cellular and biomolecular processes to develop technologies and products that help improve our lives and the health of our planet.
In macroeconomics, the focus is on the demand and supply of all goods and services produced by an economy. Accordingly, the demand for all individual goods and services is also combined and referred to as aggregate demand.
Newcomers to economics often assume that economics is about money and resembles finance. But money is only a small part of economics. Economics, rather, is the study of how people allocate resources among themselves, and that makes it a social science. That viewpoint wasn't always accepted, and still isn't by some overly mathy economists today.