Sorry for the stupid question, but please could somebody explain me what does POS INTERESTS mean ? Thank you.
POS means proof of staking. There are ways of blockchains work, some of the coins requires you to mine them, some of them requires you to use your storage, some of them wants your band with or whatever. Proof of Stake wants you to keep your wallet online all the time and hold a certain amount of the coin itself. If you use any coin that uses the POS system on their wallet than you will get the coins, put them on your wallet, keep your wallet online 7/24 and than they will give you a certain interest to you for it. Sometimes its 3-4% sometimes its extravagant like 50% a year.
In the end you will end up with money constantly just to have the coins on your wallet and staying online. That way you are basically putting your money into a bank savings account but instead of dollars you are using some other coin you believe that will get higher in price.