It contained at least three to five divisions along with artillery, air defense, reconnaissance and other supporting units.
It could be classified as either a combined arms army (CAA) or tank army (TA); and while both were combined arms formations, the former contained a larger number of motorized rifle divisions while the latter contained a larger number of tank divisions.
Modern field armies are large formations which vary significantly between armed forces in size, composition, and scope of responsibility.
For instance, within NATO a field army is composed of a headquarters, and usually controls at least two corps, beneath which are a variable number of divisions.
A battle is influenced at the field army level by transferring divisions and reinforcements from one corps to another to increase the pressure on the enemy at a critical point.