Used good

A secondhand or used good is one that is being purchased by or otherwise transferred to a second or later end user. A used good can also simply mean it is no longer in the same condition as it was when transferred to the current owner. When "used" means an item has expended its purpose (such as a used diaper), it is typically called garbage, instead. Used goods may be transferred informally between friends and family for free as hand-me-downs, or they may be sold for a fraction of their original price at garage sales or in church bazaar fundraisers. Governments require some used goods to be sold through regulated markets, as in the case of items which have safety and legal issues, such as used firearms or cars; for these items, government licensing bodies require certification and registration of the sale, to prevent the sale of stolen, unregistered, or unsafe goods. As well, for some high-value used goods, such as cars and motorcycles, governments regulate used sales to ensure that the government gets its sales tax revenue from the sale.

Secondhand goods can benefit the purchaser as the price paid is lower than the same items bought new. If the reduction in price more than compensates for the possibly shorter remaining lifetime, lack of warranty, and so on, there is a net benefit.

Selling unwanted goods secondhand instead of discarding them obviously benefits the seller.

Recycling goods through the secondhand market both reduces use of resources in manufacturing new goods, and diminishes waste which must be disposed of, both significant environmental benefits. However, manufacturers who profit from sales of new goods lose corresponding sales. Scientific research shows that buying used goods reduces carbon footprint and CO2 emissions significantly compared to the complete product life cycle, because of less production, raw material sourcing and logistics. Often the relative carbon footprint of production, raw material sourcing and the supply chain is unknown. A scientific methodology has been made to analyze how much CO2 emissions are reduced when buying used goods like secondhand hardware versus new hardware.

Quality secondhand goods can be more durable than equivalent new goods.

Secondhand goods may have faults which are not apparent even if examined; purchasing sight unseen, for example, from an Internet auction site, has further unknowns. Goods may cause problems beyond their value; for example, furniture may have not easily seen bedbugs, which may cause an infestation which is difficult and expensive to eradicate. Faulty electrical and mechanical goods can be hazardous and dangerous. This is especially a big issue if sold to countries that do not have recycling facilities for these devices, which has led to an issue with electronic waste.

...
Wikipedia