A Bitcoin base-layer transaction takes 10 minutes to confirm and can cost $5 to $50 during bull markets. You cannot buy a $3 coffee with those economics. The Lightning Network is the Layer 2 solution that fixes this.
How Payment Channels Work
Lightning creates 'payment channels' between users off-chain. Two parties lock up Bitcoin into a multi-sig wallet, and then rapidly ping balances back and forth instantaneously. Only when they want to close the tab do they settle the final balance on the main Bitcoin blockchain.
Through mathematical routing, you don't even need a direct channel with the coffee shop. The network routes your payment through interconnected nodes automatically.
The Micropayment Revolution
Because Lightning fees are measured in 'Sats' (fractions of a penny), it enables true micropayments. You can stream 10 cents to a podcast creator for every minute you listen, or pay 1 cent to read a single news article, completely bypassing subscription paywalls and Visa minimums.