Whatever the wing's mission, every wing conforms to the overall concept of "one base, one wing, one boss." Wing commanders most often hold the rank of O-7 (Brigadier General).
Numbered Air Force: A numbered Air Force (Example, 7th Air Force) is usually assigned for geographical purposes, and primarily used only during wartime. In peacetime, they generally only consist of a limited number of headquarters staff who's job it is to prepare and maintain wartime plans.
Major Command (MAJCOM): Air Force Wings usually report directly to MAJCOMs. Air Force MAJCOMs within the Continental United States are primarily organized by mission. For example, Wings who's primary mission is to fly combat missions (fighters and bombers) would likely be assigned to the Air Combat Command. Wings who's primary mission is training would likely be assigned to the Air Force Education & Training Command (AETC). Overseas, MAJCOMs are generally organized by regional area. Examples would be PACAF (Pacific Air Forces). Wings located in the Pacific Region (Hawaii, Japan, Korea, etc.) would usually be assigned to PACAF. Another example would be USAFE (United States Air Forces Europe), which control most wings assigned to Europe.
Air Force: MAJCOMS report directly to Headquarters, Air Force.
There is no set size (number of personnel) assigned to any specific element. The size of an element of command depends primarily upon the type of unit and mission. For example, an aircraft maintenance squadron would have a different number of airmen assigned than a medical squadron because it has a different mission, different equipment, and therefore different requirements.