Abstract. The primary function of the Fine Guidance Sensor (FGS) is to provide continuous pointing information to the Observatory. The FGS will image two separate regions of the JWST field of view onto two independent 2k x 2k infrared focal planes arrays, which will cover a wavelength range of 0.6 to 5 µm. Once in fine guiding, the FGS will provide continuous pointing information to a precision of ≤ 5 milli-arc seconds at an update rate of 16 Hz for J 18.5 magnitude stars. In order to fulfill its functions, i.e., Identification, Acquisition, Track, and Fine Guide, the FGS will require calibration. In this paper, we present a brief overview of the FGS design, its operations, and its calibration