The soroban

The soroban is the japanese abacus, that evolved from the chinese abacus (the suanpan) by removing one heaven bead and one earth bead, to only keep the bare minimum to interact with numbers.

What distinguishes it from the suanpan, is not only its number of beads, but also the shape of the beads. They are biconal, (made of 2 cones), with a thin slice that made it easier to manipulate bead and move them up and down.

The parts

the soroban parts explained
The frame
The frame is the black outline that holds together the soroban parts.
The beam
The beam (also called the reckoning bar) is the bar that splits the soroban in 2 horizontally.
The rods
The rods or columns are the stem that holds the beads. Their number defines the size of the soroban. Most of the time, it is 21, but that can vary from 13 to 31 or even more. The bigger the soroban is, the more numbers or the bigger the numbers you can put on it.
The beads
The beads are the basic part of the soroban that are able to be moved on the rods. You can move them up or down, given they current position.