There are two types of drones, Combat Drones (CD) and Scout Drones (SD).
You use scout drones to be your eyes in sectors that you are not currently located in, these
drones will report any activity in the sector they are placed to you directly. You can then
use this information in any way you see fit.
Combat drones can be used to stake claim on a sector, these drones will broadcast a message
to all passing ships telling them about your claim. You can set the message to be anything
you want. Combat drones will also fire upon any player that is a member of an enemy alliance.
If you wish your drone to fire upon everyone that passes through that sector, you can
set its stance to aggresive. If you wish it to do nothing when anyone passes through the sector
you can set its stance to passive.
The amount of drones you can carry on your ship is unlimited, that is why there is
no maximum amount displayed next to your drone count.