A Sword is a close-up combat weapon. It has a sharp blade which was usually one-sided (some were double-edged), therefore it is good at slashing and stabbing. Swords were popular many years ago around the middle ages, but after the invention and continual improvement of firearms, the sword slowly faded from practical use (arguably this is more due to the difficulty in learning to use a sword effectively compared with guns, rather than any inefficiency in the weapons themselves). Once trained, a swordsman can do things someone with a gun can't, but guns are much easier to train with, and they're far more popular. There are still a few isolated cases of swords in use, but in general, they are no longer practical. A sword is usually about 1ft. long from the hilt to the tip of the blade. A weapon related to the sword is the Knife. While swords are no longer used in typical wars, it's still a dangerous weapon to confront.
Swords were typically used as slashing weapons, but when plates of steel were used as armor, swords become more pointed and flexible to stab through chinks in the armor. Though some swords are used in martial arts
A sword is not simply just one type but many types varying in size and weight. There were types of swords known as long swords, which were around the size of half your body and were effective because of their speed and weight. Short swords were not far off from being considered daggers, they were used by Greeks and Romans in arenas, they were most commonly known as the Gladius. Another type and probably the last type ever to be popular was the rapier, a very light, quick using precise sword. They originated from Spain but other countries put them to their own style as well, it took great skill in using one and thus the sport fencing was put in place as to learn such a skill.