What I Already Know About My Topic

I know that there are some pretty big differences in how dressage and hunter/jumpers work a horse's body. I also know that both disciplines use different types of horses so that their build and confirmation supports their tasks.
In dressage you're going to want a horse that is built more upright in the front so that they mostly support themselves with their hind legs so that they can free their shoulder for a nicer stride. Dressage horses also typically have a lot of bend in their front legs throughout their movement where as hunters dont want a ton of  "knee action".
In hunter/jumper they look for different qualities in a horse. Head carriage isn't as severe in hunters as it is in dressage. The horse doesn't need to be as "on the bit" or "round" in how their head and neck falls. Not to mention the fact that the build of hunter/jumpers is more level from the top of their butt, to their back, and to the poll (the bone between the horse's ears).
The movements in dressage are very UP and DOWN. You would want your horse to spring off of every step to get the most elevation you can achieve. In hunters the movement is typicaly sweeping, steady, and forward (but not fast).
And though all the support and weight dressage places on a horse's hocks is tough, hunters affect the impact of a horse's legs greatly when bringing them over larger jumps.

Hunter Jumper

 Dressage