Short answers, pulled from the story.
Output in economics is the quantity and quality of goods or services produced within a given economic network during a given time period. The network can be a firm, an industry, or a nation, and the output may be consumed or used for further production.
It is national output, not large amounts of money, that makes a country rich. National output is considered essential in macroeconomics because it represents the real goods and services an economy creates.
Output and income are identical in economics: when a particular quantity of output is produced, an identical quantity of income is generated, because the output belongs to someone. This is treated as an identity, meaning it holds true regardless of the values of any variables.
Economists broadly agree on three basic sources of economic growth: an increase in labour usage, an increase in capital usage, and an increase in the effectiveness of those factors of production. Anything that reduces labour, capital, or their effectiveness will cause a decline in output or slow its rate of growth.
Net output, sometimes called netput, is a quantity in the context of production that is positive if it is produced by the production process and negative if it serves as an input to that process. This signed framing allows producers and economists to treat inputs and outputs within a single mathematical framework.
The profit-maximising output condition equates the relative marginal cost of any two goods to their relative selling price. The ratio of marginal costs can also be read as the slope of the production-possibility frontier, which shows the rate at which society can transform one good into another.