Styles Part
Style information in a WordprocessingML document is stored in the Styles part within the package, which is stored via an implicit relationship from the Main Document or Glossary Document part of relationship type http://schemas.openxmlformats.org/wordprocessingml/2006/styles and has a content type of vnd-openxmlformats.officedocument.wordprocessingml-styles+xml. 
The styles part stores two types of style information for the document:
- Style definitions 
- Latent style information