Could someone explain very simply what negative interest rates are?

Normally, when you have a savings account, interest causes your balance to increase over time.
Negative interest means your balance decreases.
So, negative interest applied to normal people means that YOU are paying the bank to store your money. (there have actually been economic “experts” suggesting that, to “discourage” normal people from saving, and instead “encourage” them to spend it.)

Applied to banks taking loans from central banks, it means that the amount of money they would have to pay back, decreases nominally over time.
So basically, the central banks pay banks to borrow money.
Of course, that would never be applied to normal people taking loans.

A central bank is an entity responsible for overseeing the monetary system for a nation (or group of nations).

With a negative interest rate, the central bank charges member banks to hold cash for them. Depositors must pay regularly to keep their money with the bank.
The idea is to force the cash out of reserve and into the market.
If you’d been debating on buying a new car and your bank started charging you 2% to hold your cash in the bank, that would likely tip you into buying the car – which is good for the economy.

It’s explained above already, but I’ll just restate in a nutshell, for us, the people keeping our money in the banks, a negative rate means we lose money every month, our bank balance actually goes down.

As stated above the negative rate can cause people to spend more money, which hopefully stimulates the economy, or take their money out of the country where it will earn more. Some people still appreciate the safety of the bank (assuming the money is safe in the particular country).

It’ll be the very next thing as soon as cash is outlawed.

You’ve probably already heard of the drive to a “cashless society”, which is fairly natural to a lot of us already with direct deposit and automatic / electronic transfers of funds for various payments and remittances. So … when that becomes mandatory, then it will be a positive requirement that your funds be in some kind of banking institution or other formal repository for funds. And then the managers of those institutions will lobby for funding for the “vital public service” that they provide, and hey presto, negative interest rates.

But y’all keep voting for more government and more control, so it’ll be exactly what you deserve.

A service charge by another name.

It is more akin to theft, really.

Negative interest rates aren’t applied to individual consumers.

This article helped me understand more than any other.

Hypothetically, if a bank loans money at 1% and inflation is 2%, the bank is losing 1% on the loaned money. So the bank just sits on its cash – it’s not worth less than it was, and the bank has plenty of cash to loan when the economy improves.
So the reserve charges the bank to hold the money. Loaning the money out at an interest rate up to and including the rate of negative interest is a savings.
This hocus-pocus has only been around since 2014. Don’t look for it to be around much longer, or to spread to the US. It’s just another bit of financial smoke-and-mirrors.