A device that forces hot water at ~9 bars of pressure through finely ground coffee. Types range from manual levers to fully automatic. Key components: boiler, pump, group head, portafilter. Pressure profiling machines can vary pressure during extraction.
Home espresso machines range from $100 (Moka pot pressure) to $5,000+ (commercial-grade). Most specialty espresso at home starts around $400–600 for the machine alone.