The term altcoin is used to refer to all alternative cryptocurrencies other than bitcoin. Bitcoin is widely accepted as being the first cryptocurrency to be developed. Many altcoins are based on the bitcoin source code. Like bitcoin, altcoins make use of distributed ledger technology and encryption to create unique digital units which cannot be duplicated.
Some altcoins are proprietary and are developed and marketed by the companies which own them. Other altcoins are maintained and developed by legal foundations. Still others are fully decentralized and are not owned or maintained by specific entities but by informal interest groups. The features which are developed for or incorporated into altcoins generally reflect either the business plan of the companies which develop them or the interests of the interest group which develops them.
New ideas which have been introduced by altcoins include proof of stake mining (as opposed to the proof of work system used by bitcoin), proof of capacity mining, obfuscation of transactions, automatic mixing and the incorporation of services in addition to currency-like features.
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