This article covers the Canon version of this subject.  Click here for Wookieepedia's article on the Legends version of this subject. 

OnACanonArticleGoToLegends

Tributary laser streams were smaller laser beams that were combined to create a superlaser. The Death Star's Mk I Superlaser had eight tributary laser streams, which were combined into one beam with an amplification nexus.[1]

Sources

Notes and references