How to tell what the individual files in the Portrait Dialogue client installation do

After installing the client version of the product there are three primary files found in the default installation path:

User-added image
MHVisualDialog.exe - starts the client version of the product (Visual Dialogue) which connects to a Dialog server instance.

MHVisualDialog.exe.resmap - a language mapping file used when running Visual Dialogue in a non-English locale. In Portrait Dialogue versions 5.2 and 6.0, multiple languages are supported. In Portrait Dialogue 6.1 English is currently the only supported language but this file is retained in case support for other languages is reintroduced for that version of the product.

PDLauncher.exe - used in the integration with Portrait HQ, specifically when launching Visual Dialogue from the Portrait HQ application.
UPDATED:  August 7, 2017