A lightsaber is a fictional energy sword featured throughout the Star Wars franchise. A typical lightsaber is depicted as a luminescent plasma blade about in length emitted from a metal hilt around in length. First introduced in the original Star Wars film, it has since appeared in most Star Wars films, with at least one lightsaber duel occurring in each installment of the "Skywalker saga". The lightsaber's distinct appearance was created using rotoscoping for the original films, and with digital effects for the prequel and sequel trilogies.
In the Star Wars universe, the lightsaber is the signature weapon of the light-side-wielding Jedi Order and the dark-side-wielding Sith Order. However, the lightsaber can also be wielded by non-Force-sensitive characters as an ordinary weapon or tool. The Jedi use different colored lightsabers (predominantly blue and green, though purple, white, and yellow have also appeared in canon media), while the Sith wield exclusively red-bladed sabers to distinguish themselves from the Jedi. The color of a lightsaber's blade is given by its power source, the kyber crystal, which is influenced by the wielder and the Force as they connect with and tune the crystal. A lightsaber's hilt is built by its wielder and is, therefore, unique in design. There are several variations outside of the traditional single-bladed lightsaber, such as the double-bladed lightsaber (most famously wielded by Darth Maul), crossguard lightsabers (used by Kylo Ren), and the Darksaber, forged by the Mandalorian Jedi Tarre Vizsla, but primarily wielded by the non-Force-sensitive Mandalorian rulers of Mandalore (including Pre Vizsla, Maul, Bo-Katan Kryze, Sabine Wren, Moff Gideon, and Din Djarin).
As presented in the films, a lightsaber's energy blade can cut, burn, and melt through most substances with little resistance. It leaves cauterized wounds in flesh, but can be deflected by another lightsaber blade, by energy shields, or by the metal beskar (found in Mandalorian armor). The blade has even been used as a tool to weld metal.