I'm just trying to explain a little bit about what you need in my knowledge on this subject.

Testnet, also known as test network, is an experimental network where programmers can test, create, even alter, features and keep track of how the blockchain network is performing. In general, testnets seek to guarantee accurate comparisons, take chances, identify the optimal model, and ensure quicker mainnet builds. To effectively test complex networks at scale, each blockchain network has its own testing methodology, standards, equipment, and certifications.

Since Ethereum is a protocol, this implies that there are numerous separate "networks" that adhere to it but do not communicate with one another. You can use the network for use cases involving development, testing, or production. It is a unique Ethereum environment. Despite the fact that your Ethereum account will function across several networks, your account balance and transaction history.