In the automotive arena, there is a generally accepted convention regarding the terms "sender" and "sensor".
Simply put, a "sensor" is a device that provides an input signal to the Engine Control Module (ECM) or Powertrain Control module (PCM), ans is tasked with monitoring a specific condition and providing the ECM/PCM with ongoing information regarding that condition. The ECM/PCM uses that information in formulating its control output(s) to various engine and/or powertrain devices. For example, a PCM may use a crankshaft position sensor's output to determine the triggering of the ignition control module, thus driving the timing of the spark to the spark plugs. However, the crank position sensor input to the PCM is normally also used as a factor in other calculations made by the PCM, as is the case with most of the many sensor inputs received by the PCM.
In the automotive sense, a "sender" is a device that has a direct control over its output device. Some examples would be a fuel level gauge, an oil pressure gauge, or a coolant temperature "idiot" light. In each of these examples, the output device (e.g., the gauge or the light) and its associated "sender" are usually components in discrete circuits.