Is a 40 watt speaker loud?

Excuse me, could you please clarify something for me? I've come across the statement "Is a 40 watt speaker loud?" and I'm a bit confused. I understand that wattage is a measure of power, but does it necessarily mean that a 40 watt speaker will produce a loud sound? I'm interested in understanding if there's a direct correlation between the wattage of a speaker and its volume output, or if there are other factors that come into play. Could you please elaborate on this? Thank you in advance for your insights.