To make this overly simple let's look at it this way. If you go with a single stage press you will only accomplish one function at a time. You put a sizing/depriming die in the Rock Chucker, punch out the old primer and set it aside. Then you pick up another piece of brass and do the same thing. Once you have all the brass re-sized and deprimed, then you go to phase two which is seating new primers in each piece of brass with a hand priming tool. Once you have primers in every piece of brass, you would then put a powder charge in each of them by hand with a little dipper. Let's say you charge 50 at a time. You would then put a bullet seating die in the Rock Chucker and seat one bullet at a time until all 50 were charged and had bullets sitting in them. You would then put a crimping die in the Rock Chucker and crimp all 50 rounds, one at a time. You would then have 50 finished rounds. (Sounds a little tedious?)
A turret die allows you to set up either three or four (sometimes 5 on the more expensive presses) dies at one time. You would pick up one piece of brass and size/de-prime it. On the down stroke you would replace the primer with a new one. Rotate the turret one space and insert another piece of brass. On that stroke you size and deprime one piece of brass while putting a powder charge (from an automatic charging unit) into the first piece of brass you put in the press. Then you put a third piece of brass in the turret. This time you are sizing/depriming, putting a powder charge in your second piece of brass, and seating and crimping your first piece of brass. If you had a four hole turret press you could seat the bullet in hole 3 and then factory crimp it in hole 4. Keep in mind that on a fully manual press YOU are rotating the dies for each repetition.
A progressive turret reloader has a mechanism for rotating the turret with each stroke of the arm, saving you that effort. A Dillon press keeps the dies stationary and you rotate the pieces of brass by pushing on an arm sticking out from the shell plate holder. Each stroke of the arm completes one finished round of whatever you are loading.
A mechanized progressive press does all the functions for you with the right attachments. All you have to do is watch.
This is an over simplified explanation for illustration purposes. The thing for you to decide is what you want to accomplish by reloading. Are you looking to learn a great deal about ballistics and the true nature of bullets and firearms. Are you looking for a greater quantity of ammo than what you can find or afford to buy. Are you looking for a truly satisfying hobby to fill a niche in your endless days of sameness? If you start small and work your way up I suspect you will discover a whole world of new aspects to shooting that non reloaders do not know exists.
It's your choice. Those of us here on THR will gladly help you begin, learn and enjoy!