Money is a positive thing for a society to have, since it provides citizens with a medium of exchange that they can use to pay for needed goods and services. Bartering was common before money became widely used, but it has limitations that make it much more inflexible than money.
Someone wishing to barter has to first find a person who has the item or service that he or she wants, and this person must also be willing to conduct a trade. In addition to logistical issues, bartering does not allow citizens to store money for future necessities.
Money may be stored or invested until it is required, allowing people to build their wealth. It also permits individuals to purchase things of all values. With bartering, the exchange is generally for an even value.