Bitcoin Test Networks
In order to facilitate development of software built to use Bitcoin as a base layer, and the Bitcoin mining node client software itself, two separate testnets have been created which are available to all users. Additionally, the node client also includes a local testing mode called 'Regtest'.
The Testnet is a separate BSV network that has all the same functionality as the Mainnet, except its bitcoins have no real market value. The Testnet serves to provide a stable testing environment for applications such that developers do not have spent actual BSV before deploying their service to the Mainnet. WhatsOnChain provides a testnet block explorer available for public use.
A faucet for acquiring testnet coins can be found here.
Scaling Test Network
The Scaling Test Network is a network specifically built for testing large blocks and sustained transaction volume. Nodes can be configured to connect to this version of the Testnet. This was created in order to segregate scaling testing from the Testnet whose purpose is for application development.
This network is created specifically to prove and and demonstrate the scaling techniques necessary to achieve the massive scale that Bitcoin was always capable of.
Regression test mode (RegTest)
The BitcoinSV mining node client can also be run in regression test mode with the -regtest command-line argument. This runs a local-only server and lets you generate blocks instantly. Regtest is useful for app development and testing purposes.