GDP stands for Gross Domestic Product, and it attempts to show the economic state of the country in a number.
It's a measure of how the economy has grown or contracted over a three month period.
The level of GDP is measured in three ways: the value of the goods and services produced by the economy, the value of goods and services purchased by households and the government, and the income generated in terms of profit and wages.
More top news
RAF veteran Andy Davies says the Royal British Legion helped him get back on his feet after problems with alcohol.
Lucy has the latest weather forecast for Wales
Plaid Cymru leader Leanne Wood has said her MPs won't back English votes for English laws until Wales gets an extra £1.2 billion a year.