JUTA is the "Government" buses. They come in many different sizes. They are all over the island. The ones in Kingston look like our local transport or public transport. The others seen on the island are varying but usually route taxis.
The Minibuses are just that. Usually a 12-16 seater bus. They are used for various things from peeps having their own Taxi business to running an approved route.
Route Taxis are just that and called that. They are red plated vehicles of varying sizes. They have been licensed by the Government to run a specific route day and night (such as we have public transit buses), such as from Negril to Sav or Negril to Lucea. They only go that route so if you are going further, you get out at the end and then get another one to continue on. I have taken one from Negril all the way to Kingston, took me 2 route taxis. The rate varies depending on the distance as some routes are quite short (such as the beach road in Negril) and cost very little (100-150 JA), and some routes are longer, Sav to Kingston (750-800 JA). These are shared taxis as the driva will fill the car to the brim to get the most money from beginning to end of his route. To catch one, you wait at the side of the road and signal by waving at the driva when he is approaching that you wish to get in. If unsure about the price, always ask before getting in! Just let the driva know where you want to be let out.
From the airport there are tons of options. Anything from a private driva to getting on a minibus with others to local resorts providing the ride in the cost of your vaca. A private driva negotiates the price with you hopefully before you have landed (meaning arranging this before you leave) but there are drivas waiting outside that are willing to negotiate when you land. A private taxi ride can cost from $60 US and up (depending on your destination) and can be quite expensive if you don't negotiate and be willing to talk to a few of them to get the best price. A ride on one of the buses to town can cost as little as $20 US depending on which company you go with. Again this can be arranged or should be before you leave and this cheaper option means you share the bus with a few other peeps and the bus does a few drops at different hotels/resorts. There are counters just outside immigration just before you go outside with options.
I am unsure about dispatched taxis in rural areas as I think this is pretty much only offered in larger cities such as Kingston and maybe Montego Bay (but unsure about Mobay). I know that there are no dispatch taxis in Negril, a private driva is used with pre-arranged pick-up times and such or you get in a route taxi to go from say the beach road to the west end.
I always use a private driva in Negril, arranging with him a price ahead of time and then calling him when I need a ride. Also do the same when heading from the airport to Negril, just find it easier and less hassle.
Hope this makes sense. Message me if you having any questions