What distinguishes espresso from regular brewed coffee?

Espresso is characterized by its preparation method, which involves brewing coffee under high pressure. This process, typically around 9 bars, extracts flavors and oils from the coffee grounds more efficiently than traditional brewing methods. The high pressure also results in a concentrated shot of coffee with a rich crema on top, which is not present in regular brewed coffee. This distinguishes the espresso's intense flavor and body from that of regular coffee, which is brewed with the force of gravity, typically without the same pressure or concentrated methodology.

The other options do not accurately describe espresso. Espresso is usually made with hot water, not cold. Additionally, it requires a finer grind compared to regular coffee, contrary to the suggestion of a coarser grind. The choice about decaffeinated beans is irrelevant to the fundamental difference, as espresso can be made from both caffeinated and decaffeinated beans, and the type of beans does not solely define the brewing method or the characteristics of espresso.