Active and approved are controls that restrict visibility and sales.
Active products can be sold through all channels including ebay, webshop and control panel. Inactive products cannot be sold. This can be used to differentiate old and new stock.
Approved products are visible and can be seen on the web shop. Unapproved products are not visible on the website front end and can only be sold from the control panel (if active).
For example, a product needs to be "active" and "approved" in order to be visible on the website and to be available for sale.