ToF camera (time of flight)
A depth camera that measures distance by how long emitted light takes to return.
A ToF camera gives a depth value for every pixel of its image, so the robot sees the distance to a table edge, a step or a child's leg, not just a flat picture. It works at close range, typically up to a few meters, and costs less than a 3D LiDAR.
It is often used for low obstacles that a 2D LiDAR misses, for docking and for hand-eye work on arms. Bright sunlight and shiny or black surfaces can degrade it, so for a robot working near big windows or outdoors ask how it copes with that.