The Playback Utility replays previously logged events to the Event Processor. 
The purpose of this utility is to take logged events and send those transactions through the Event Processor at either the original transactions speed or accelerated to review past movements or to simulate operations.  Transactions would be sent to an Event Processor that is separate from the production system so as not to send erroneous/duplicate data.
The screen below shows a typical Playback display.

In this application you can select a time frame for which records are to be selected for playback.  The playback speed allows for accelerated playback through the Event Processor, this prevents you from having to review transactions in real time.  Additional Filters can be specified to limit that data is used, this can be done by selecting a specific item using the Select Items (seen screen below).

A specific SQL selection string can also be defined by selecting the SQL where option.   The following shows how a typical screen showing this might appear.

Below is a brief description of the Playback command buttons.