What is the difference between inflation and deflation?

I don’t think there is any difference, they are the same.

Dolly Parton and Clarissa Flockhart.

Inflation in economics refers to a general increase in the price level in reference to a single currency. Deflation is the opposite, referring to a general decrease in the price level. Governments measure the rate of inflation by looking at a variety of products that average customers buy and noting their price trend. This is called the Consumer Price Index (CPI). And increase in CPI means there is inflation, while a decrease in CPI mean there is, or was at the time of measurement, deflation.
Milton Friedman quipped that “Inflation is always and everywhere a monetary phenomenon” meaning that it is the result of the government increasing or decreasing the money supply or a change in the velocity of money.

To put it in less technical terms than @arpinum did (although I’ll GA that one), inflation is when money is worth less than it used to be (inflating how much it takes to buy something, prices going up), and deflation is when money is worth more than it used to be (deflating the amount you need to buy something, because prices are going down).

Inflation and deflation refer to what the prices are doing.

A tip, try wiki-ing or googling answers first before asking them here on Fluther. We (I doubt that it’s simply me alone who has this sentiment) appreciate questions which have been asked because the users really can’t find the answers anywhere else. Else you’ll find that your answers will probably lead to a letmegooglethatforyou link.

Inflation=increase
Deflation=decrease

in layman’s terms (i think):
inflation = prices go up because the actual value of the currency is less (e.g. if inflation increases tomorrow, a $2 happy meal at mcdonalds may cost $3 b/c each dollar is worth less)
deflation = the opposite?