Answer:
By channeling goods and resources to those who value them most, trade creates value and increases the wealth created by a society's resources. ... A person who buys and sells goods or services or arranges trades.
Step-by-step explanation:
Well it's very simple. You are probably good at some things and suck at others. You may have a friend that suck in something that you are good at and are good at something that you suck at. Meaning it's more efficient if you do the things that you are good at for that friend and he/she does what he/she are good at for you. You both save time and effort by doing that trade.
Alternatively you don't trade and make/do everything you need on your own. The advantage of this is that should something happen that makes you unable to trade, you'll survive. It's still better to trade. But should your region for some reason lose its food delivery system there will be no one to trade with in order to get food unless some are self sufficient enough to be able to share.