These [Lightning] channels are not a separate trusted network on top of bitcoin. They are real bitcoin transactions.

Micropayment channels use real bitcoin transactions… this is not a trusted overlay network —payments in micropayment channels are real bitcoin communicated and exchanged off-chain.

Lightning Network White Paper, page 4, Section 2: A Network of Micropayment Channels Can Solve Scalability

Creating a network of micropayment channels enables bitcoin scalability, micropayments down to the satoshi, and near-instant transactions. These channels represent real Bitcoin transactions, using the Bitcoin scripting opcodes to enable the transfer of funds without risk of counterparty theft, especially with long-term miner risk mitigations.

…Bitcoin can scale to billions of users without custodial risk or blockchain centralization when transactions are conducted securely off-chain using bitcoin scripting…

Lightning Network White Paper, page 55, Section 12: Conclusion