The “7” means that the robot has 7 joints. Most collaborative robots have only 6 joints or less. Having 7 joints or 7 axis points or 7 DOF (degrees of freedom) means that the robot can reach around something. For example, if your robot is operating a machine and it only has 6 joints, then you have to put the robot directly in front the work, which leaves limited room for a person to work alongside it.