Altcoins are the cryptocurrencies other than BitCoins, launched after the big success of BitCoins in 2009.
Altcoin is combination of two words "Alt" for Alternative, and Coin remains same. Altcoins are formed by the basic framework provided by BitCoin. Most of the Altcoins are P2P and involve "Mining" (To create new coins from solving some mathematical problems by some machines) that causes the cheaper transaction fees.
The main reason why these Altcoins were or are forming? Due to flaws of BitCoin and they also try to compete with Bitcoin by creating new feature to improve and surpass limitations of Bitcoin. Like Litecoin which take 1 or 2 minutes in transaction at other hand Bitcoin takes 30 minutes to 2 hours or more.
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