Modern navigational systems should function properly and dependably not just when a GPS signal is present, but even when it is absent or maliciously blocked. Traditional navigation systems fail to work in many GPS-restricted settings, such as inside, caverns, canyons, or when GPS is jammed or not even available such as an outer planet scenario. Many researchers are now proposing a variety of methods to address these constraints. Visual-Inertial Odometry (VIO) is one of several approaches for dealing with GPS-denied navigation that has piqued the scientific community's curiosity. Only a tiny portion of the offered methods can produce desirable accurate results and be considered for applications where acceptable Size, Weight, and Power (SWaP) are restricted, due to large processing needs and insufficient resilience when addressing complicated real-life scenarios.