Ever wanted to add articles to your Joomla! site from another source? If you've ever tried, you've probably run into a few issues—for example, articles that have been created directly in the database will not get indexed by the Smart Search component.
The main reason problems arise when adding articles directly to the database is the implementation of the assets table (used in Joomla! sites since 1.6). The assets table keeps a row for content items as it relates to Joomla!'s ACL system.
For simplicity's sake, just know that Joomla! relies a lot on the assets table and we'll need to make sure we add a row when adding an article programmatically.
Luckily, Joomla! makes it easy to import articles through the API.