No one is charged interest here, but interest is paid to users under certain conditions.

For instance, if you "stake" your HIVE into HIVE POWER (HP), you will be paid an additional 2.89% each year. So, for every $100 you hold, you will be paid an extra $2.89 at the end of a year as a 'thank you' for holding the funds here. It is akin to how a bank pays interest if you let them hold your money in a Savings Account.

It is also similar to this: say that you visit a vendor near your house and buy a coffee or a Bubble Tea every single day. After a couple of weeks, the vendor might say, "You are such a regular customer! Here is a tea today, for free, as a thank you!" He is showing "interest" in your business by giving you a small reward.

By the way, this is the sort of question that we answer every day in TheTerminal's Discord. 🙂