Gross domestic product (GDP) ?

The market value of all final goods and services produced within nations geographic borders during a period of time.

The components of the GDP are Consumption, Investment, Government Purchases and Net Exports (Exports-Imports) .Stated as the following formula,
Y=C+I+G+NX or Y=C+I+G+(X-M)

Nominal GDP
The value of all final goods based on the prices during the time period of production.
Real GDP
The value of all final goods and services produced during a given time based on the prices of a selected reference year.

What is Money ? 

Something that has a real value and can be exchanged for a good or a service.
It can serve as a medium of exchange, a unit of account or a store of value.
Money at different times has been steel, gold, stones, cigarettes, goats, camels, oils and wheat.

The primary function of money is to be widely accepted in exchange for goods and services, provide a common measurement of the relative value of the goods and services and the ability to hold value over time.

Money itself provides no return, so people and businesses who hold cash or cheque account balances incur an opportunity cost (forgone interest).

We need money for three reasons. Transactions demand our daily needs spending, precautionary demand in case of an emergency and speculative demand for financial assets or investments.

What is a recession?
• A recession is a significant decline in economic activity spread across the economy, lasting more than a few months usually two consecutive quarters, normally visible in real gross domestic product (GDP), real income, employment, industrial production, and wholesale-retail sales.
• A recession begins just after the economy reaches a peak of activity and ends as the economy reaches its trough.

What happens in a recession?
• During a recession people spend less money since household incomes decrease. Consequently companies make less money, resulting in lower earnings and thus lower share prices. As a result the stock market gets hit first and hardest.
• The lack of demand that hits the companies causes them to decrease inventories, cut down on productions and draw on their stored resources. This phenomenon makes employers lay off employees that are no longer needed causing unemployment to go up.
• Work becomes scarce, there are more employees than employers and this causes the general wages to go down.

How to determine a Recession early?
• Watch the value of the dollar; If the value of the dollar is falling in comparison to other currencies it can be an early indication of an impending recession.
• Keep tabs on the Gross Domestic Product (GDP). Decrease in the GDP for more than a single consecutive quarter is an indicator of economic recession.
• Keep an eye on the Leading Economic Indicators (LEI).
• Money Supply,
• Manufacturing workers' average number of hours,
• Stock prices,
• Consumer expectations,
• Building permits,
• Capital goods orders.

What to do in a recession?
• The first thing that we have to do is to keep a roof over our family’s head. Since the risk of lay-offs drastically increases and we can lose our jobs any time.
• we should take care of our basic needs of food and shelter.
• We should start putting cash into a reserve fund.
• Be very careful with your spending and budget wisely,
• Hire a movie instead of going to the theatre,
• Drive less if possible,
• Cook at home rather than eating out.

Conclusion
• Loss of jobs or higher unemployment rate,
• Higher interest rates,
• Lack of business investment and activities,
• Rising prices in some cases,
• Stock value falls,
• Dollar value decreases.