Explain · Like I'm five version
Interest rates in terms of a central heating thermostat
Interest rates are just like a big dial on your radiator that decides how hot or cold the whole country feels.
When the big bosses at the bank turn the dial up, they make it much harder for everyone to borrow money to buy things like a new car or a house. It is like turning the heating up to make the room feel expensive and stuffy, so you decide to stay still and save your pennies instead of spending them. Most people stop buying treats when the costs go up, which helps slow everything down when things get a bit too busy.
If they turn the dial down, they make borrowing money very cheap and easy for everyone. It is like making the room nice and cosy, so you feel happy to splash out on a new toy or a fancy cake from the shop. When the money flows around like warm air in a house, shops get busier and people start to buy more things again. The bank keeps wiggling that dial all day to make sure the country stays at just the right temperature.
Sometimes the dial gets stuck or the boiler starts making a funny clanking noise, so they have to be very careful not to make the house too hot or freezing cold. They want us to be comfortable, but they worry that if we have too much money to spend, the price of milk and bread will go up too fast. They spend all their time watching the thermometer, hoping we stay perfectly happy and warm.
Where the analogy breaks downA radiator does not have to worry about the price of a loaf of bread if it gets too hot.