A juggling prop is an object that people juggle - anything that can be juggled can be called a "prop". The three standard props used in toss juggling are balls, rings, and clubs. Each of these props is thrown with a different technique, and most objects that can be juggled are similar to one of these and are juggled with a similar technique. There are 1-dimensional props (long, narrow objects like clubs, sticks, batons, canes, or knives), 2-dimensional props (large, flattish objects like rings, hoops, plates, disks, or frisbees), and 0- or 3-dimensional props (objects of any size that aren't in the 1-D or 2-D categories, like balls, beanbags, rocks, cell phones, or watermelons).
Balls are generally considered to be the easiest of the three main props to juggle. The most common type of juggling balls are beanbags, which are fairly easy to collect, and don't roll away when they're dropped. Juggling balls are normally small enough that several can be held in one hand at a time, but some jugglers use larger balls, which are good for head bouncing and other soccer tricks and are easier for an audience to see.
Rings are much bigger than balls, which makes them look good when juggled, and also makes them more difficult to juggle. For some people rings are easier than balls, especially for numbers juggling, because they are also lighter and very thin, so they collide less, and they are the easiest prop to collect. 13 is the highest number that has been flashed with both balls (beanbags) and rings. Rings and clubs are normally turned sideways when doing outside throws, so the sides of the rings are visible from the front. Rings can be placed around the neck, which makes it possible to do tricks with them that can't be done with balls and clubs, such as pull downs. Pancakes are another trick unique to rings.
Clubs are the most difficult of the three main props, because they naturally rotate in the air and normally need to be caught on the handles to make collecting possible, to keep from making the juggling unnecessarily difficult, and to make it look good. Canes are a variation of this prop that are even more difficult because they're longer, and to make them look good and to prevent collisions, they need to be kept from rotating on their own axes in addition to catching the right end. Sticks are another variation that are harder to run than normal clubs, but easier for flashing high numbers. The rotation speed and direction can be varied to turn basic patterns with clubs into more difficult tricks, such as 3 club doubles, 5 club singles, flats, reverse spins, and helicopters.
- Props category on Juggle Wiki