Top Highlights

• Knowing how something works often makes you more adept at working with it, extending it, or fixing it when it breaks.
• Content management systems (CMS) handle the creation, storage, retrieval, description or annotation, and publication or display of a variety of content types.
• extensibility and the separation of content persistence from content display.
• It is not sufficient to install blogging software, write a few posts, and hope the world shows up on your virtual doorstep; you need to create what Tim O’Reilly calls an “architecture of participation.”
• Core files are all files in the wp-admin and wp-includes directories and the majority of the files in the root WordPress directory. The wp-content directory holds all of your custom files, including themes, plugins, and media.