Shadow Replication Technique
The Shadow Replication Technique (Kage Bushin no Jutsu; English TV: Shadow Clone Jutsu; Viz Manga: Art of the Shadow Doppelganger) is a Jōnin-class technique in which the user, unlike the Replication Technique, can create real, tangible duplicates of his/herself. The user's chakra is equally spread among each of his/her clones, so the more clones a user makes, the more chakra is used up distributing it to each of the replications. It is for this reason that most ninja limit their use of this technique and the number of replications they make to four or five at a time, as the technique takes a large toll on their chakra reserves. However, Naruto, because of his abnormally large chakra reserves, uses this technique regularly when in combat, and often creates up to 100 clones at a time. Naruto also uses this technique as a basis for an array of other techniques, such as Rasengan.
 Mass Shadow Replication Technique
The Mass Shadow Replication Technique (Tajuu Kage Bushin no Jutsu; English TV: Multi Shadow Clone Jutsu; Viz Manga: Art of the Mass Shadow Doppelganger)
Rasengan, primarily the Fourth Hokage's technique, now used by Naruto is a Wind-Style Jutsu, which was taught to him by Jiraiya. He uses the Shadow Replication Technique to create this successfully. Naruto has his hand prepared for the technique while a clone inputs chakra into Naruto's hand. By combining Rasengan with another element he created a Shuriken (throwing-star) Rasengan.