Sabers, a type of sword, have been made and used for centuries, and their exact origins are unknown, although historians suspect that they may be related to Middle Eastern blades. Although they are no longer used in warfare, these blades often show up on military dress uniforms as an indicator of rank and status. A derivative of this sword is also used in sport fencing, although a true saber and a fencing saber have little resemblance.
These swords are heavy, with a single cutting edge and a slightly curved blade. The handle is also heavy and arched, protecting the knuckles and fingers of the hand. Originally, they were designed for cavalry members. Throughout the 19th century, sabers were used in active warfare all over the world, perhaps most notably by Napoleon's soldiers.
Over time, the horse was phased out of warfare, eliminating the need for mounted soldiers except on ceremonial occasions, and swords were replaced by guns and other long range weapons. However, the saber had become such an iconic weapon that many militaries came to preserve it as a ceremonial blade. It's often possible to see sabers on display in military parades and at other formal events involving members of the military, and by tradition many of these blades are sharp and fully usable.
A fencing saber is quite different. These have a "V" or "Y" shaped blade, and are lightweight yet strong. Like a traditional saber, the fencing version has a single cutting edge, and blows with the side of the blade as well as the tip are acceptable hits in competition. To prevent injury, the tip is bent, creating a button so that the blade will bend when it comes into contact with someone, rather than penetrate the person.
Because blows with the side of the blade are acceptable in saber fencing, this style of fencing is distinctive and unique. People who practice this type of sport fencing tend to be extremely agile, using an assortment of movements to corner their opponents. The entire upper body is an allowable target in this fencing, allowing people to score hits in a variety of creative ways.