Software Simulation help

Serena_hm

hello everybody ,

I'm seeking for a quick answer ...and I will be really thankful for your help
well , I'm working on Neplan software for load flow study and I have question related to shunt reactors ....
in the Element properties block there are 3 control mode options ( fixed , Discrete , & continuous )

what's the difference between the 3 of them exactly !?
and where/when I should use each one !?