| More docs on the ARB website. See also index of helppages. Last update on 22. May 2026 .

Main topics: ARB: a Short Introduction arb.pdf (PDF) | Related topics: Trees Helix Node Display Setup (NDS) PT_SERVER: What Why and How SAI Sequence Associated Information What are Species ? Selected Species and Cursor Position What is an Alignment ? ARB Command Interpreter (ACI) What are Marked Species? Search and Replace Tool (SRT)
# Glossary What do we mean if we talk about ... ## What do we mean if we talk about ...
### ALIGNMENT Subdatabase containing homologous sequences (different 'alignments' can be stored along with the species information). See ´What is an Alignment ?´ for more information. ### ACI ARB Command Interpreter. ACI is a simple programing language for calculating special species information (eg. G+C Content..) See ´ARB Command Interpreter (ACI)´. ### EDGE Branch within a tree defined by nodes ### FIELD Container for 'species' associated information ### MARKED SPECIES Marking of 'species' defines the datasubset which is analyzed by the ARB tools. See ´What are Marked Species?´. ### NAMES There are two kinds of name fields (for species, genes, etc.). name Identifier for 'species' entries. Should be generated automatically using the name server. full_name User defined full name of the species,... ### NDS Node Display Setup: defines information which is displayed at tree nodes. ### NODE Internal: connects branches of a tree Terminal: free end of branches representing 'species' ### PT_SERVER Server using a special form of the ARB database for rapid similarity searching (automated alignment, probe design/check) ### SAI Sequence Associated Information ### SELECTED SPECIES The 'selected species' is that ONE species which has been selected by using any of the following actions ARB_NTREE/Search + click onto one search result ARB_MERGE/Transfer species + click onto one search result (here there is one selected species in each of the two involved DBs) clicking on the species name in the tree display in ARB_NT placing the cursor into the sequence of a species in ARB_EDIT4 The currently selected species will be displayed in the 'Species info window' ### SPECIES Database entry containing a sequence and associated information. Not necessarily consistent with a taxonomic species ### SRT Search and Replace Tool allows to search substrings in a string and replace them by another substring (see ´Search and Replace Tool (SRT)´).