If I set "3000 cycles" in DOSBox , what does it mean exactly ?

Does it mean DOSBox is going to execute 3000 instructions per second, regardless the instructions ?
Or, does it mean DOSBox will run 3000 CPU cycles / ticks each second, some instructions (eg: DIV) taking more time than some others (eg : ADD)

I know some emulators take care about how much time each instruction take, is it the same for DOSBox ?