Well I looked up thee meaning between the too so I didn't mess up the definition I gave you :P but from what I see jodhpurs run all the way down the length of the leg and are typically meant to be folded up and worn with paddock boots and breeches stop somewhere around the calf with smooth ends and are typically made to be worn with tall boots, but if you look in a lot of catalogs, breeches are sized to run all the way down to above your ankle, not to your calf. I just wear breeches when riding with a paddock boot and half chaps. The folded area on the bottom of the jodhpurs and the "stirrups" that came with the ones I bought bother me for some reason.
Jods are worn over paddock boots, often cuffed, and in h/j land are only worn by kids. (I know in some countries, and I think saddle seat people? Adults wear jods as well). The rule around here is if you're young enough to show with your hair in braids with bows you need to wear jods with garters.
Breeches are worn under tall boots.
I ride in tights usually. They run all the way down the leg, are very strechy, and are SUPER comfy! I wear half chaps or tall boots when I ride FYI. ;) Breachs are sometimes made of a not a streachy material too.