Timothy B. Lee:
Three startups are getting ready to launch one of the most ambitious and important cryptocurrency experiments since the creation of bitcoin itself. Called Lightning, the project aims to build a fast, scalable, and cryptographically secure payment network layered on top of the existing bitcoin network.
Essentially, Lightning aims to solve the big problem that has loomed over bitcoin in recent years: Satoshi Nakamoto’s design for bitcoin is comically unscalable. It requires every full node in bitcoin’s peer-to-peer network to receive and store a copy of every transaction ever made on the network.
This is probably the best explanation of the Lightning Network that I’ve found so far. It still sounds complicated, but then everything about BitCoin is complicated.