Samurai swords are called katana in Japanese. They symbolize the spirit of Bushido, the Way of the Warrior. In popular imagination they are incredibly sharp and should only be used by a true samurai. The first picture is a poster for the movie Kill Bill, showing Lucy Liu drawing a samurai sword in front of her eyes.

The second picture shows drawings of samurai swords from an old Japanese book. There was a whole genre of such books with illustrations like this.

The third picture is a shot from the movie Ghost Dog with Forest Whitaker playing a samurai. In this picture he is seen training with a sword on the roof among his pigeons.

The forth picture is a poster for the movie The Last Samurai, showing Tom Cruise with a couple of samurai swords.