The word surplus is a term that is handled in the economic context as the excess amount of something. The surplus can occur in the consumer and in the producer. The first refers to the economic gain of the buyer, when acquiring a product with a specific price, which in turn is an amount lower than the stipulated price, or a higher real price in the market. The second is based on the law of supply and demand, and refers to the monetary contribution that it receives as an extra profit that accrues outside the cost of production, by trading its product at a price higher than that established in the market. That is, the surplus is a kind of extra profit that is obtained from a lower price, or higher than that considered for the purchase of a merchandise.
The surplus is equal to the saving, since it means any benefit that some organism receives and that is not consumed. For example a company, the family, a government entity, etc. By this is meant that all entities can obtain savings as long as they do not consume more than necessary. The income of a family group will be equal to the sum of the salaries of its members; if this salary is spent in its entirety, then there will be no surplus that allows them to save.
Historically, the surplus began to emerge with the entry of livestock and agriculture, for example that part of the production that was left over after the demand was satisfied, was exchanged for other products, for social status, or recognition. Many families of the time only had at their disposal the products that they harvested, so they used the production that exceeded them and exchanged it for other products.
