When you access a contact record in Redtail, you'll notice new menu items in your Left Menu Bar underneath Contacts (these menu items only appear when within a contact record):
Here we'll take a look at Timeline. If you click that option from this menu, you'll see the Timeline area for the Contact:
The contact's Timeline displays a list of actions taken upon the record, including updates to their data, Notes added, Activities, Workflows, etc. While the default setting is to view All, you do have a Filters button in the top right corner of the timeline that will allow you to filter by a specific type of action or view All actions:
Note that if you scroll to the bottom of the contact's Timeline that more timeline entries will continue to load (until you reach the end of entries on the record).