Many know the look and sound of the lightsaber and automatically know it comes from Star Wars. If you are wondering how did the concept of the lightsaber come to be and why, you have to watch the Star Wars Featurette: The Birth Of The Lightsaber.
The featurette covers the influence for Star Wars and a weapon matching their ideals. You see a clip from Star Wars: Episode IV A New Hope, where Obi-Wan Kenobi introduces the lightsaber.
According to Lucas, the “laser swords” were the technological edge for the Jedi because of their capability to deflect incoming fire as the Jedi are not “warlike, aggressive fighters.”
…not as clumsy or random as a blaster. An elegant weapon for a more civilized age.