go after vs preface

go after

• To pursue an object or a goal. 

• To pursue in attempt to catch another. 

preface

• To give a preface to. 

• To introduce or make a comment before (the main point). 

• An introduction, or series of preliminary remarks. 

• A title or epithet. 

• The beginning or introductory portion that comes before the main text of a document or book. 

• The prelude or introduction to the canon of the Mass.