Pachyderm is a very simple Content Management System (CMS). It allows users to add and edit pages, create categories of pages to group together, upload and manage images and media, and that's about it. This system is not intended to provide every and any option you can think of - it is intended to be simple for the end user.
When creating this CMS, the first thought that went into building it was "Time Savings." Most clients I build websites for are smaller businesses who do not have need for high-level enterprise applications. Mostly, their sites are a means to augment their advertising, and provide their clients a means of contacting them. So, my thoughts were, "How can I get their sites up and running quickly?" "How can I change their site design when they return to me?" and "How can I speed up the process of content edits that normally require my time and coding to make updates?"
Those three questions provided the framework for what Pachyderm CMS does:
It is not a blog engine. It is not a complex system intended to handle multiple custom plugins (the Pachyderm time-line calls for only 2 plugins - shopping cart, and affiliate tracking). It is intended to allow people to edit their content in a simple interface and no more. If you are looking for complex and fix-it-all types of content management systems that allow for more complex modifications, check out this Wikipedia page.
To get started, take a look at the Pachyderm features, or just dive right in to the documentation.