The Stellar Mainnet is the live and operational blockchain network of Stellar, where real transactions occur and digital assets hold actual value.
The Stellar Testnet is a sandbox environment separate from the main Stellar network, allowing developers to test and experiment with applications without using real assets or affecting the live blockchain.
Horizon is an API for interacting with the Stellar network.
Soroban is a scalable, developer-friendly smart contracts platform, designed for seamless integration with the Stellar blockchain.