Economists use GDP (Gross Domestic Product) to see how different countries are doing economically. Here’s a simple breakdown of how it works:

1. What is GDP?
   GDP tells us the total value of all the goods and services made in a country within a certain time, usually a year. It shows us how healthy and productive the economy is.

2. Comparing Economies:
   By looking at GDP, economists can easily compare different countries. For example, if Country A has a GDP of $1 trillion and Country B has a GDP of$500 billion, we can see that Country A has a bigger economy.

3. Per Capita GDP:
   To understand how well people live in a country, economists often use something called GDP per capita. This means they take the GDP and divide it by the number of people living there. For example, if Country A has 100 million people and a GDP of $1 trillion, each person would have about$10,000. If Country B has 50 million people and a GDP of $500 billion, each person there would also have about$10,000.

4. Factoring in Costs:
   Sometimes, economists adjust the GDP numbers using something called Purchasing Power Parity (PPP). This helps to account for how much things cost in each country, making it easier to compare them accurately.

In summary, while GDP is not the only thing to look at, it’s a helpful way to get a better understanding of how countries compare economically.