Standard websites always have 'pages' and in the case of Wordpress they also have 'posts' which are used for the 'blog posts'.
Often business require more than just pages and post and this is where custom content comes in.
Examples of custom content for a website:
- Portfolio items
In fact I've built websites using all of the above
Advantages of using custom content for websites
- To increase the conversion rate in many ways - such as optimising the user experience
- Makes it possible for the search engine results page to list the details directly instead of just showing a link and description
- Makes it easier to optimise the website for search engines
- Opens up the possibility of the website using advanced information architecture
- Last but not least - it makes it super easy for the website manager to add content without any risk of breaking anything. No knowledge of html required.