What is the real purpose of private blockchain for example in Ethereum ? I mean found a lot of tutorials online about creating a private blockchain, creating an accounts there, setting coinbase accout, start mining and so on, but none of them tells the reason why it's there, what use i can get from that ? Is that just for study purposes ? The ethers that i mined on my private blockchain, are they are real ethers ? Can i transfer them to real wallet ?
Private blockchains exist so that companies can pretend to be innovative by using a blockchain for no real purpose. But that's just been my personal experience, maybe someone else has something positive to say :)
The ethers mined on a private blockchain exist only on that blockchain. As far as the main Ethereum network is concerned, they do not exist. It's a completely separate cryptocurrency.