A concrete syntax tree or parse tree is an (ordered, rooted) tree that represents the syntactic structure of a string according to some formal grammar. In a parse tree, the interior nodes are labeled by non-terminals of the grammar, while the leaf nodes are labeled by terminals of the grammar. Parse trees may be generated for sentences in natural languages (see natural language processing), as well as during processing of computer languages, such as programming languages. Parse trees are distinct from abstract syntax trees (also known simply as syntax trees), in that their structure and elements more concretely reflect the syntax of the input language.http://en.wikipedia.org/wiki/Parse_treeБлин, и далее совсем уж скользкая ассоциация, но не могу удержаться:Вот в одной не малоизвестной книге по энэлпэшному профилю очень похожие картинки :)