Source tree and target tree

A source tree is the source structure (of a profile) filled with data, that is, after the process of parsing (phase 2).

A target tree is the target structure (of a profile) filled with data, that is, after the process of mapping (phase 3).

Note: From a practical point of view, the main difference between a structure and a tree is that any node (and its fields and possibly subnodes) of a structure can occur multiple times in a tree. A tree can also contain the structure itself several times (→ records). See also section When does the parser start a new record?

Note: A source and target tree can consist of several records, each containing a subtree. We call the entire construct the source/target tree, i.e. starting from a (from your perspective imaginary) root we have the records and these, in turn, contain the subtrees.