Inflation as defined by the oxford dictionary is a general increase in prices and a fall in purchasing value of money. Inflation is actually the
The more money you have in circulation the less its worth would be and that’s a problem.
For example if a massive inflation takes place and an average person, David has a million dollars but that million dollars actually worth is only to buy an apple. Then in this case the worth of a million dollar has gone down. The loss of purchasing power at a time is called inflation and when inflation gets out of hand money becomes worthless.