The Ethereum network is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.
Ethereum is unique in that it allows developers to create their own cryptocurrency tokens and launch their own decentralized applications (dapps). These tokens can be used to represent virtual shares, assets, proof of membership, and more.
Decentralized applications have many benefits over traditional centralized applications. They are more secure, because there is no central point of failure.
They are also more censorship-resistant, because there is no central authority that can censor them.
However, decentralized applications also have some challenges. They can be more complex to develop and deploy than traditional centralized applications.
They also tend to have slower transaction speeds and higher fees than centralized applications.
So, which network should you use when sending Ethereum? That depends on your needs. If you need a quick and easy way to send ETH tokens, then the main Ethereum network is a good choice.
If you need a more secure and censorship-resistant platform for developing and deploying decentralized applications, then the Ethereum testnet or one of the Ethereum forks may be a better choice.