Hi! Welcome to the forum!
Hi,
i would to know, what are the main importatnt alternative cryptocurrency to bitcoin??? example: litecoin, megacoin.....
There isn't "important" altcoin but there are "most used" altcoins. Litecoin, Dogecoin, NXT are some of them.
- Why these kind of coin have need to exist? because bitcoin have some problem, or issue, and this type of coin are born to resolve this issue, or for another mission?
Some coins came with a few features which Bitcoin doesn't have. But most coins came into existence to scam people.
- this other coin can work with the same process of bitcoin (blockchain, private and pubblic key, process of mining??)
As They are coins made cryptographically, they work almost same. However, there are different algorithms for different coins. Private key and public key works similarly but coins using different algorithms, private keys and public keys will be(look) different. They are various way how a coin is minted. Bitcoin uses POW for it but other coins uses POW, POS etc...
- the alternative cryptocurrecy can be considered a true alternative of bitcoin or these are weak to challege bitcoin??
Altcoins aren't a "challenge" to Bitcoin at any means.
Thanks
Anytime.