Terminology
First, for our purposes, what do we mean by “drill”? It’s Close Order Drill or Foot Drill, whether stationary or while marching in a formation: squad (element), platoon (flight), color guard, etc. The word also includes manipulation of a rifle, Rifle Drill.
Unarmed Drill is any movement performed without a piece of equipment: rifle, sword, saber, or flagstaff (guidon and colors staff). Armed Drill is obviously performed with equipment.
There are three types of military drill: Ceremonial, Regulation, and Exhibition. For a complete breakdown, read the article, What is a Military Drill Team?
For an historic perspective, you can read A Brief History of American Drill and Ceremonies. This graph may also help you in your understanding of drill classifications.
Purpose and Results
The purpose of military drill is to move a group of individuals from point A to point B in an efficient manner. In Basic Training or Boot Camp drill instills military bearing, discipline, and a sense of accomplishment. It teaches adherence to standards, response to commands, individual coordination, teamwork, esprit de corps (the spirit of the formation/body from an historic perspective), alertness, urgency, confidence, followership, attention to detail, and leadership. It gives a group the ability to render respect, show honor, and uphold tradition. It’s also a form of exercise.
Competitive drill and ceremonies, mainly seen in high school JROTC but also in college SROTC and some who drill independently of the scholastic system, brings in more benefits: exhibition drill brings out creativity in designing the marching, body movement, and rifle manipulation.
One of the biggest advantages can be seen in competitive regulation and exhibition drill for squads, platoons, and color guards. This comes in the form of a wide range of leadership skills:
The ability to teach the team the processes of the performance. Delegation of responsibilities while maintaining ultimate responsibility for the performance outcome. Memorization of the routine: commands, marching, and (rifle, flagstaff, and/or body) movement. The ability to think quickly to ensure the team stays within the time limit and physical boundaries and recover from possible mistakes.
Military drill has multiple benefits, some intangible and some to be realized possibly years later. All of these benefits come to fruition in battle, that’s why we march in the military, but they also are realized in all kinds of aspects of life in general.