FOC sensor vs sensorless
As a general rule, FOC requires EITHER of those sensors, but some can function without the external encoder. So the term "sensorless" is referring to the versions where there are no EXTERNAL sensors, i.e. there is no encoder required. As a general rule this means a loss of accuracy at a complete standstill, so it is not recommended for applications needing 100% torque at zero speed such as a hoist control application. that is because at a complete standstill, no movement in the rotor means there is no change in the current flow, so any error in the current measurement results in possible loss of torque in the control algorithm.

There are a few manufacturers who have released highly advanced forms of FOC wherein the internal current sensors are accurate enough to allow FOC performance even at standstill but without the external encoder. These are referred to as "encoderless" FOC in order to maintain differentiation from "sensorless" vector control. But I personally would not stand under a hoist expecting it to hold a load when the mechanical brake is released unless there was an encoder on the motor. An absolute encoder lets the drive know the exact position of the rotor when the drive is required to produce an exact amount of torque in that hoist to keep the load from dropping and running away.