Lightning payments are transactions taking place on the Lightning Network, a layer-2 protocol built on top of the Bitcoin blockchain. Lightning payments allow for near-instant and low-cost transfers of bitcoin between parties, making it an attractive alternative to traditional on-chain bitcoin transactions.

The Lightning Network was first proposed in 2015 by Tadge Dryja and Joseph Poon to address the scalability issues facing Bitcoin. As the number of transactions on the Bitcoin blockchain increases, the time it takes for transactions to be confirmed and added to the blockchain also increases, leading to long wait times and high transaction fees. The Lightning Network is designed to alleviate these issues by allowing for off-chain transactions that could be settled quickly and inexpensively.

To understand how Lightning payments work, it's first important to understand the basics of the Lightning Network itself. The Lightning Network is a network of payment channels that are created between two parties. A channel allows parties to the channel to transact bitcoin without having to record each transaction on the Bitcoin blockchain.

Two parties create a payment channel by creating a two-of-two multi signature Bitcoin address and funding  it with bitcoin. Once the channel is funded, the parties can transact with each other by exchanging bitcoin through their channel. These transactions are not immediately recorded on the blockchain, and thus are called “off-chain transactions,” but are tracked privately by the Lightning protocol.

As the parties transact with each other, the balances attributable to each of them in the payment channel changes. Either party can close the channel by agreeing to a closing transaction with their channel counter party or, if the channel party is non-cooperative,  submitting the last transaction to the Bitcoin blockchain. This closes the channel and distributes the funds to the two parties according to allocation tracked by the Lighting protocol.

Lightning payments take advantage of the fact that transactions inside a channel are executed very quickly, allowing for near-instant transfers of bitcoin between participants. For example, if Alice wants to send Bob some Bitcoin, but they don't have an established payment channel, they can create one by funding it with some Bitcoin. Once the channel is funded, they can begin exchanging instant, off-chain transactions with each other.

To send a Lightning payment, Alice would create an off-chain transaction that sends some of her Bitcoin in the channel to Bob. Bob would then have to acknowledge the transaction by signing a new one that incorporates the new information. This exchange of information  happens very quickly, and the payment can be settled in seconds.

Lightning payments take advantage of the fact that transactions inside a channel are executed very quickly, allowing for near-instant transfers of Bitcoin between participants. Because Lightning payments don't require each transaction to be recorded on the Bitcoin blockchain, they are much faster and cheaper than on-chain Bitcoin transactions. This makes them an attractive option for small transactions that might not be cost-effective on-chain.

Lightning payments are becoming increasingly popular in the Bitcoin community and beyond. Many Bitcoin wallets and exchanges now support Lightning payments, and the network has seen significant growth in recent years. Additionally, companies like Lightspark are building enterprise-grade solutions to make transacting on Lightning simpler and easier for businesses.