Microeconomics is the study of how individuals and firms make decisions in a world of scarcity. Scarcity is what drives Microeconomics. Microeconomics is a series of constrained optimization exercise. Economic agents (such as firms or individuals) try to make themselves as well off as possible (make the most of what you can)
One of the most important things in microeconomics is the notion of opportunity cost. Which is basically saying that every action, or every inaction has a cost. You could’ve been doing something else instead, there’s always another option. Ex: if you used your money to buy a shirt, you could have used that money to buy pants instead but you decided to use it on a shirt. Everything you do has a next best alternative that you could’ve done instead. Nothing is free, there’s always a trade-off. You build people’s lives, and businesses, and understand the decisions that drive our economy.
Model: a description between any two or more economic variables or any two or more variables. These aren’t laws, by and large, they’re models. So we don’t have a relation between energy and mass which we can write down and be done. We have models which are never 100% true but always pretty true, “pretty” by being somewhere between 10% to 95% true.
