An economic recession is broadly as a downturn in the GDP(gross domestic product) iof a nation for at least two successive quarters, ie, 6 month.
If the GDP of a country drops by at least 10 per cent, then this is called a depression. By these standards, the last depression America suffered was the great depression in the 1930s.
The worst drop in recent times was during the oil shock in the 1970s.
The national bureau of Economic Research in the US is considered the official arbiter of recessions, but it doesn't define a recession by the school book measure of two or more consecutive quarters of economic contraction as measured by GDP. It states that a recession is a significant decline in economy, lasting more than a few months.
India is currently witnessing a slowdown. The GDP is growing at a healthy 7 per cent plus, but this is still slower than the average 9 per cent-plus recorded in the previous three financial years. As of now, there is no threat of either a recession or a depression