Economics terminology that differs from common usage

Economics terminology can sometimes use words in different ways than they are used in everyday language. For example, when economists talk about "investment" they mean buying something with the hope of getting more money in the future. This is different than how most people use the word "investment," which is to put money in a bank or stock market for the purpose of making money over time. Another example is the word "economy," which usually means the financial situation of a certain area or country. In economics, "economy" refers to all of the exchanges (buying and selling) that happen in an area, even if this exchange isn't related to money.