A turret press is basically a single stage press but the dies mount in a movable "turret" that holds an entire set of dies in one turret.
The advantage is that you can set up all your dies in the turret and then you won't have to remove and install dies every time you change from resize to expand or to seater or crimper. They are all setup and to change to the next die you just turn the turret (or some presses auto-index the turret for you).
You still are working on only one cartridge at a time.
A progressive has the turret feature of a turret press, in that all the dies are setup in a turret on top of the press, but also there is a moving shell holder that indexes shells individually through the stations for each die. Thus, you are working on three cases at one time.
For example, on a Lee Pro 1K:
Pull lever, that loads shell 1 to the decap/resize die.
Pull handle. Shell 1 decaps/resizes, as handle goes up, shellplate advances shell 1 to the expander/powder fill and inserts a primer. Shell 2 is loaded at the decap/resize die.
Pull handle. Shell 2 decaps/resizes. Shell 1 expands and gets powder dumped. Shells advance to next station, shell 2 gets primed, and shell 3 gets loaded at the decap/resize die.
Set a bullet on shell 1, pull handle. Shell 1 gets seated/crimped. Shell 2 gets expanded/filled. Shell 3 gets resize/decapped.
Shells advance to next station. Shell 3 gets primed. Shell 1 (now a finished round) drops off into bin. Shell 4 gets loaded at the resize/decap. Process continues, with a finished round dropping out of the press with every handle pull.
Hope that helps.