A crash course in changing the world.
Barter is old-fashioned of exchanging a thing that you want to trade to the thing that you want, that you are going to trade it with your thing. In old days, there is no money, so they only can trade things with things, for example a watch with a kg of rice. But, once there is money, it became a lot easier, because the buyer can just use money to trade/buy with the things they want/need. Also, if we use barter we will not know the value and we also don't know what to trade with, if we trade valuable things with non-valuable things, then we are at a loss, but if we trade non-valuable thing with valuable thing, then we earn.
For the future money, I think that we should save our money that we earn, unless it's in an emergency situation. This is because if we keep saving money, there will be more money and after a few years it will be a lot and we can buy more and better things with it. But if we waste our money and not save it, in the future we will not have any money to spend for ourselves. I think we should just save our money by ourself not other people or the bank, because we will not gong to worry about our money if we hold it by ourself and we will never loss the money unless we lost it accidentally. Also, maybe we can buy a coffer to keep our money in it and also we can put it in our own house. This I think can also be safe, because we can keep it ourself and coffer need to have key or combination to open it, so the person who have the key or who knows the combination is the only one that can take and put the money. But, to buy a coffer I think it's better to buy better ones like the one that will never brakes and will not brakes if there is fire/explosion.