IIRC lightning network transactions only use as much electricity as 10 emails, although I guess at some point a real Bitcoin transaction will happen eventually.
Yeah pretty much. A lightning channel is a bit like putting money down as a retainer for a lawyer, or putting a deposit down in a hotel.
The real transaction happens at the beginning, and another transaction happens at the end when the channel closes and we settle out who gets the remainder.
It uses the Lightning network, which is a separate network using off-chain transactions. The Lightning network crams upwards of infinite transactions into a single on-chain transaction, called a payment channel.
The difference is that the Bitcoin transaction will cause millions of computers to waste a serious amount of electricity calculating hashes over and over.