Which one will be the solution to the bitcoin scalability problem (Dream of instant payments with low fees)?
Lightning Network:
off-chain protocolIt would feature a P2P system for making micropayments of digital cryptocurrency through a scale-free network of bidirectional payment channels without delegating custody of funds or trust to third parties.
[1]SegWit2x:
block size limitwas a failed contentious hardfork outlined in the New York Agreement that intended to double the block size limit. The hardfork has been denounced as an attempt made by CEOs and owners of large Bitcoin businesses to introduce changes to the currency's protocol and development cycle with ulterior motives.
[2]