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Main topics: ARB: a Short Introduction Glossary | Related topics:
# Trees OCCURRENCE DESCRIPTION ## OCCURRENCE
### ARB_NT
## DESCRIPTION
### A tree consists of two types of 'nodes': tips or terminal nodes: species connected to exactly one father inner nodes: hypothetical ancestors connected to one father (and in the binary case to two children). A group_name may be assigned to an inner node; in this case, the node and all its children become a group. <ARB_NT/INFO_MODE/M> ### There are significant differences between phylogenetic trees and binary trees:
    phylogenetic trees                      binary trees:
    -------------------------------------------------------------------------
    unrooted                                rooted
    inner nodes have n children             all inner nodes have two children
### Since binary trees are much easier to handle, ARB converts phylogenetic trees to binary trees.