very well Mentioned above....
Just to add a little more. The rod maker check out for spine of the blank (Spine - natural tendancy of the flex of the blank). If he wants to make a spinning rod out of the blank he would place the guides below the spine flex and for casting rod he would place the guides above the spine flex.
Many a times you can use a spinning rod along with baitcasting reel (I have personally done it n number of times). However if the fish is over the line rating and you want to bulldoze it with full drag, the rod may break as it is getting the opposite flex.
Boat rods can be both spinning as well as casting model, however they are on the heavier side where the line rating is pretty high for you to bulldoze and fight a big fish. (Do not confuse boat rod with only trolling rod, there can be various boat rods but for various application).