From the publisher:

This is an English translation of Descartes’ seminal discourse, with an original essay by Richard Kennington. This text is designed to provide the student with a close translation, notes, and a glossary of key terms, facilitating access to ideas as they originally were presented and helping to make the translator’s work transparent.

Focus Philosophical Library translations are close to and are non-interpretative of the original text, with the notes and a glossary intending to provide the reader with some sense of the terms and the concepts as they were understood by Decartes’ immediate audience.