Modern movies that are set (theoretically) in the Middle Ages often show people fighting with long, thin fencing foils. But these are nothing like real medieval swords--and contrary to many other movies, you cannot "fence" with a medieval sword. They were too heavy. They were meant for cutting and whacking.
The basic sword was long, reaching from where it hung on one's belt down to mid-calf or lower. It was sharpened on both sides of the blade. The handle was usually made as an integral piece of metal with the blade. Because you didn't want your hand sliding down, there would be cross-pieces, the hilt. This meant that the sword overall was in the shape of a cross, which seemed extremely significant to those at the time who tried (not entirely successfully) to make knighthood something inherently Christian.
As part of their knighthood training, boys would learn to fight with swords, starting with wooden swords, working up to blunted weapons, and finally being allowed to use sharp blades. In a battle between knights, they would start by trying to knock each other off their horses with their lances, then, when they were unhorsed, they would draw their swords and start raining blows on each other. One defended against sword blows with a shield, not by using one's own sword as a fencing foil. One could theoretically lay about with a sword from on horseback, but it was dangerous--especially for the horse.
Because medieval blacksmiths did not have furnaces hot enough to melt iron, they had to make a fire as hot as they could with charcoal and bellows, to soften the metal enough to be worked. To make a sword, the iron would be repeatedly heated in the fire, folded and pounded. In essence, they were making carbon steel. Especially fine blades were made in parts of the Middle East. ("Damascus steel" was renowned in the west.)
Swords were very expensive and greatly prized. We have few medieval swords, because they would be in use until they totally wore out. They do however show up in medieval art, and in the early Middle Ages a few would be put in the tombs of the most powerful.