There is also signet, which is a different testnet that works more like Liquid where blocks aren’t mined by hashing, instead they’re just signed by a set of known keys. Mutinynet is another signet.

Arguably signet is better for testing Lightning as the blocks are more predictable and shenanigans like Lopp’s attack can’t happen - testnet is useful for testing anything that needs the chain to behave more like actual Bitcoin (mining software, ASICs, reorgs etc) 

 was actually trying to check the difference the other day😂, really appreciate the explanations mate 💯