The HTTP tracking API (i.e. the
Piwik\Tracker component) receives raw analytics data, which we call log data.
There are four types of log data:
Log data is never used directly for Piwik reports, archive data is used instead. The only exception is the Live plugin which uses log data to generate real-time reports.
Log data is represented in PHP as
Piwik\Tracker\Visit objects, and is stored into the following tables:
log_visitcontains one entry per visit (returning visitor)
log_actioncontains all the type of actions possible on the website (e.g. unique URLs, page titles, download URLs…)
log_link_visit_actioncontains one entry per action of a visitor (page view, …)
log_conversioncontains conversions (actions that match goals) that happen during a visit
log_conversion_itemcontains e-commerce conversion items
The content of those tables (and their related PHP entities) is explained in more details in the Database schema guide.