Robots in Perpetuum - as you may see in their descriptions - are all specialized in an activity (laser warfare, harvesting, etc.). These additional capabilities all depend on the manufacturing faction of the series, because the various fractions prefer a different kind of warfare or industrious activity.
The exact bonus can be found on the information chart of a robot, just click on the bonuses tab. The effect column shows the special ability that the robot performs with greater efficiency. The percentage next to it - basically 5% - shows the basic level bonus, which can be multiplied by installing the proper robotics extension.
For example, if You own a Prometheus robot, it has a base 5% bonus on light lasers. If you install the 3rd level of the relevant extension (this case the basic robotics extension), the total bonus will be 3x5=15%.