The basic protocol allows you to move bitcoins between two entities without putting every single transaction on the chain - only 2 blockchain transactions are needed for unlimited Lightning Network transactions.

Then, on top of this, there's a framework for moving money through the network - I send money to someone I have a Lightning Network payment channel with, they send it to someone they have a channel with, etc, until it gets to you. The great thing about this is that I can prove everyone isn't cheating, and if they are, I can immediately reverse my transaction - I haven't lost any money.

So the result of this is the creation of a network of payment channels which have very very low costs to process payments, aren't embedded in an industry that's difficult to get into (you or I could process payments just by joining the network), and have no ability to try and take a larger cut under the guise of a "points" or "cashback" system as you can easily switch to a different channel which takes a smaller cut.