Projects and coins continually add new functionality to be successful future implementations must not harm the blockchain here testnet  work begins a cryptocurrency testnet is essential for development developers can test on this network without affecting the main network developers programmers and experimenters use them the actions of  the test network have no effect on the main blockchain developers make near identical genesis blocks for blockchain clones this marks the testnet blocks and currency. This divides the two blockchain and inhibits coin transfers this technique prevents testnet coin from being transferred to the mainnet original network this solved the testnet 2 problem and prevented fraud Mining was also resolved current testnets don't raise the cryptocurrency mining difficulty this makes mining bitcoins in a tesnet so easy that it nullifies their value testnet are identical to their original network except for mining and marking genesis blocks if a new implementation works on the testnet it should also operate on the mainnet.