When you shop for a robot vacuum, you will keep hitting two navigation systems: lidar and camera-based (often called vSLAM). They map your home in completely different ways, and the right one depends on your house and habits.
How lidar works
Lidar spins a small laser on top of the robot, measuring distance to walls hundreds of times per second to build a precise floor map. Because it uses light it sends out, it works perfectly in the dark.
Strengths: fast, accurate maps; reliable in low light; consistent room-to-room paths.
Weaknesses: the raised laser turret can be a few millimeters taller, so it may not fit under the lowest furniture. It also does not "see" objects on the floor unless paired with extra sensors.
How camera navigation works
Camera systems use one or more cameras plus software to recognize features in your home and triangulate position. Newer ones add AI obstacle recognition that spots cords, shoes, and pet waste.
Strengths: lower profile; excellent at identifying and avoiding specific objects; often better in cluttered homes.
Weaknesses: struggles in very dark rooms; some people dislike a camera roaming the house, though images stay on-device on reputable brands.
Which to choose
If your home is tidy and you clean at night or want flawless mapping, lidar is the safer pick. If you have pets, kids, and a floor that is never fully clear, a camera-based obstacle-avoidance model will get stuck far less often.
The best flagships now combine both: lidar for mapping, cameras for obstacle avoidance. If your budget reaches that tier, you get the strengths of each.