In order to orient aerial vehicles such as unmanned aerial vehicles and guided munitions toward intended target points, it often becomes vital to acquire the correct information about the states of the targets during the flight of the vehicles. One of the most widely-used ways to achieve this task is the utilization of seekers. Physically, the measurement capability of seekers is restricted due to some physical, optical, and electronic limitations such as limited field-of-view (FOV), atmospheric transmittance, and noise effects. Regarding these characteristics, basically two types of seekers are employed in the relevant applications: strapdown or body-fixed seekers and gimbaled seekers. The strapdown seekers are directly mounted on the considered vehicle body. Therefore, their measurements become relative to the body fixed reference frame of the missile. For relieving the FOV limitations of the strapdown seekers, the gimbaled seekers are preferred in some of the implementations. In this scheme, the seeker is mounted on a platform supported by two orthogonal gimbals and stabilized by means of rate gyro feedbacks. This way, the FOV range of the seeker is increased considerably. Also, the line of sight (LOS) angle and the LOS angular rate can be measured directly independently of the missile motion. This study deals with the comparison of these two kinds of seekers according to certain criteria involving mounting properties, FOV, angle and rate measurements, guidance method utilization, measurement methods, major sources of measurement errors, and cost. A general evaluation is submitted at the end of the work.