Abstract syntax tree

A tree representation of the syntactic structure of a sentence; similar to a Parse tree, but usually ignoring literal nonterminals and nodes corresponding to productions that don't directly contribute to the structure of the language (e.g., parenteses, productions used to encode operator priority and so on). May represent a slightly simpler language that the parse tree, for example, with operator calls desugared to function calls, and variations of a construct folded into one. Can be represented using as trees or terms, and described by an algebraic data type or a regular tree grammar.

[Wikipedia]