It varies according to demand.
An airfield is a place where airplanes can take off or land, without the need for terminals or paved runways.
Runways
An Airfield is an area of fields and runways where aircraft can park and take off and land
Vietnam has four runways
There are no paved runways in Antarctica. Airplanes land on skis, not wheels, on runways of ice.
It is an advantage if fixed wing aircraft take off and land into the prevailing wind. Therefore runways are angled to allow this to occur. Larger airports will have a selection of runways to allow a choice to be made depending on the current wind direction.
there are 5 runways.
Honolulu International Airport has six runways.
A.P Hill Army Airfield Biggs Army Airfield Bicycle Lake Army Airfield Condron Army Airfield Coleman Army Airfield
7
Senior Airport Authority or Senior Airfield Authority "should be designated early in the planning process by the joint force commander (JFC). The SAA is responsible for the control, operation, and maintenance of an airfield to include the runways, associated taxiways, parking ramps, land, and facilities whose proximity directly affects airfield operations." Reference AFTTP (I) 3-2.68 Ch. 1-5
Changi Airport has two parallel runways, 02L/20R and 02C/20C.