A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more accurately.
The original fire-control systems were developed for ships.
The early history of naval fire control was dominated by the engagement of targets within visual range (also referred to as direct fire). In fact, most naval engagements before 1800 were conducted at ranges of 20 to 50 yards (20 to 50 m). Even during the American Civil War, the famous engagement between the USS Monitor and the CSS Virginia was often conducted at less than 100 yards (90 m) range.
Rapid technical improvements in the late 19th century greatly increased the range at which gunfire was possible. Rifled guns of much larger size firing explosive shells of lighter relative weight (compared to all-metal balls) so greatly increased the range of the guns that the main problem became aiming them while the ship was moving on the waves. This problem was solved with the introduction of the gyroscope, which corrected this motion and provided sub-degree accuracies. Guns were now free to grow to any size, and quickly surpassed 10 inches calibre by the turn of the century. These guns were capable of such great range that the primary limitation was seeing the target, leading to the use of high masts on ships.
Another technical improvement was the introduction of the steam turbine which greatly increased the performance of the ships. Earlier screw-powered capital ships were capable of perhaps 16 knots, but the first large turbine ships were capable of over 20 knots. Combined with the long range of the guns, this meant that the ships moved a considerable distance, several ship lengths, between the time the shells were fired and landed. One could no longer eyeball the aim with any hope of accuracy. Moreover, in naval engagements it is also necessary to control the firing of several guns at once.