Definition
Inflation is an economic phenomenon in which the overall prices of goods and services keep rising and money loses its purchasing power. Think of how $10 buys fewer apples than it used to: things get more expensive, and at the same time the real value of the money you hold goes down.
Why the snack stays the same size but the price goes up
Almost everyone has had this moment. The ice cream cone that cost 50 cents when you were a kid now costs $1.50. It didn't grow three times bigger, and it doesn't taste three times better. The taste and size are the same, but the number on the price tag jumped.
Usually this isn't because ice cream became especially rare. It's often because prices rose across the whole economy, so the same money buys less. One cause is that more money is moving around in the economy. A single dollar used to buy plenty of things. Now you have to hand over several dollars to get the same thing.
On the surface, inflation looks like prices going up. But look underneath, and it is really the value of money going down. When money gets weaker, you have to pay more of it every time you buy something.
Why do prices keep rising?
There are two main roads that lead to inflation. The first is when people's desire to buy (demand) is much bigger than the amount of goods on the market (supply). When a hot new sneaker draws a crowd, sellers naturally raise the price. In the same way, when buying fever runs high across the whole economy, prices go up.
The second is when the cost of materials and labor needed to make things goes up. If the price of the fuel that runs factory machines soars, or the flour a bakery needs gets pricier, the shop owner has little choice but to raise prices to avoid losing money.
On top of that, pumping lots of money into the economy to fight a slowdown can push prices higher. If the amount of stuff in the world stays the same but there's a flood of money, each dollar is worth less, and prices can rise.
A little more precisely
Inflation isn't always bad for the economy. Central banks in many countries aim for "mild inflation," with prices rising around 2% a year. If prices fall instead (deflation), people tend to put off spending and companies hold back on investing. A little inflation gives the economy some breathing room against that risk, and it leaves central banks space to cut interest rates when times are bad.
On the other hand, hyperinflation, when prices spiral out of control, throws a whole society into chaos. If a loaf of bread costs several times more overnight and you need a wheelbarrow full of cash to buy it, nobody trusts money anymore and nobody saves.
That's why central banks raise or lower their benchmark interest rate to keep inflation at a reasonable pace. It's like tending a campfire: you adjust the flame so it doesn't die out, but it also doesn't burn the house down.
Common misconceptions
Inflation means things themselves become more valuable.
No single item got better or rarer. Prices rose across the board, so the same money buys less. And the causes aren't only a bigger money supply. They include surging demand and supply-side shocks like higher raw material and labor costs.
Rising prices are always bad for the economy.
Mild inflation of around 2% a year is considered a level that lowers the risk of deflation and helps the economy run smoothly. That's why many central banks aim for it.
Where you meet it
A snack that cost $1 ten years ago now costs $2.
You keep $10,000 in an account that pays no interest for 10 years, and prices rise so much that it buys less than it used to.
In one sentence
Inflation is when money loses value and prices rise across the board. A moderate amount is manageable for the economy, but too much can cause serious chaos.