A wind cone (windsock) at an airport primarily provides what information to pilots?

Why →A wind cone shows the direction the wind is blowing and, by how far it stands out, a rough indication of speed. It extends fully in a strong wind and droops in a light one. The open end faces into the wind, so aircraft take off and land toward the open end. Wind information is essential for a remote pilot judging drift and control margins.

The trap →A windsock does not display a runway number or an altimeter setting. It indicates wind only. The active runway is inferred from wind direction, because aircraft favor the runway most closely aligned into the wind.

Field note →The narrow end of the sock points downwind, the direction the wind is heading. Wind is named for where it comes from, so a sock pointing east indicates a west wind.