How do testnet faucets work?

Testnet faucets are services that distribute test network cryptocurrencies, such as Ether, to developers and testers. They operate on test networks, which mimic the real Ethereum network, allowing for the development and testing of smart contracts and DApps without the risk of losing real value. By providing their test network Ethereum address, users can receive a certain amount of test Ether from the faucet, enabling them to conduct various testing activities.