According to the National Center for Atmospheric Research, wind exists because of the movement of air and the differences in air pressure within the atmosphere. When high-pressure air moves toward low-pressure air, the difference in pressure leads to a faster air current or stronger wind.
The National Center for Atmospheric Research explains that wind can be described as air that is moving with both direction and speed. Wikipedia explains that there is also wind in outer space, which is the movement of gases or charged particles from the sun throughout space. Wind direction is always expressed in terms of the direction from which the wind is blowing, never the direction in which it is going. Easterly winds are those that come from the east and move towards the west.
In addition to direction, wind speed is described by terms such as a breeze or gale. Gale-force winds are much higher and capable of doing severe damage, while a small breeze generally only moves a few miles per hour. According to the National Center for Atmospheric Research, the speed of air is determined using the Beaufort Scale, which measures wind speeds between 1 mph and 73 mph. The Beaufort Scale also divides winds into 12 categories for easy measurement.