a casting rod would be a beachcaster,a rod designed to chuck out baits to the required distance,and would normally have a stiffish action,a spinning rod would be for casting lures up to 2oz,and would have a soft action so you would be able to "feel"the lure work in the water.a jigging rod is a rod for "jigging"soft jellies,shads,pirks of a boat.But thats a simple definition!a beachcaster can be bought with a "soft action"for flatties or bass,a spinning rod can be got with a stiff action for big fish,like a pike rod.there is a rod for every kind of fish,i would own 14 different rods but ive been collecting for a while.to start i would recommend a stiffish beachcaster rated 4-8oz for the bigger fish,a beachcaster rated 2-4oz, for smaller fish like flatties,and a spinning rod with a test curve 1 1/2 to 2lb.that should cover all your fishing.
Noel