Power HP = Torque (ft-lb) x RPM / 5252

from this formula alone, Power is dependent of Torque. Now, for example in order to get a 200 HP

If RPM = 6000, Torque = (200HP x 5252)/6000 = 175 ft-lb, it means it is with higher RPM to get that 200 HP
If RPM = 5000, Torque = (200HP x 5252)/5000 = 210 ft-lb, it means it is with lower RPM to get that 200 HP

high HP, low Torque; it means you need a high RPM, just imagine if you have very low torque so you need very high RPM
low HP, high Torque; it means a lower RPM which more fuel-efficient