'stagnation' is quite general and it means to slow down or stop (or stop growing) So a stagnating economy is one that is growing. 'recession' is used generally to describe a shrinking economy. More technically, it often has a specific definition. I think the Bank of England define it as an economy that has contracted (or not grown) for two successive quarters. 'a downturn' describes a decline in economic performance (another pretty general term) There's also the phrase 'economic crisis' which is used more or less as synonyms for all of the above. I think only recession has technical definitions, and these will be defined by a National Bank or a Government, etc. You can find better and more detailed explanations here: http://www.investopedia.com/terms/r/recession.asp#axzz26GgrfYoO