Other than the Flow mainnet network, Flow testnet can be used to test applications and contracts before deployment to mainnet.
During a round of network upgrade, Flow testnet is updated first. Hence, testnet can be used to test against the latest node software, Cadence and core contract changes which will eventually be available to mainnet.
How To Access These Networks?
Get Flow blockchain data from Access Nodes, both REST and gRPC endpoints are available. Get the current status of mainnet and testnet networks.