During a battle, how the military is deployed is considered using tactical forces. This includes firepower, mobility, shock value and protection. Depending upon the situation, the commanders may utilize ground forces, navies, air strikes and mobile units such as cavalry or tanks. Synchronization is required to ensure that the tactical forces have maximum impact.
Setting determines what forces are available. In medieval times cavalry and foot soldiers would be employed, while in a futuristic story, all kinds of computer-generated weapons would be used.
Your task is to do a little research to determine what tactical forces are logical for your story. You might want to download pictures and details into a reference folder. Find out how the weapons and units would be used, the distance in which weapons are effective and what technologies make the weapons successful.
Next write a scene in which military forces are utilized to effect outcome in battle. You might involve a small strike team or an entire army. The bigger the number of forces, the harder it may be to direct them in battle.
Include dialogue even though narrative description is important.
Have fun with this one.