This video shows two comparison based sorting algorithms: Bubble sort and Quick sort.
The algorithms are demonstrated by robots sorting balls by hue. Comparison based sorting algorithms must make decisions based solely on pairwise comparison results. This is visualized by the robot's short-sightedness, which forces them to perform pairwise comparisons in a very pronounced manner.
The video culminates in a contest. Each algorithm is presented with an identical series of balls and they compete to see which finishes the sorting task faster. In addition to raw speed, the number of comparisons they perform is also measured. Advanced viewers will notice bubble sort performs comparisons quicker than quick sort. This is because quick sort has to move around a lot between comparisons. Quick sort aims at reducing the number of comparisons, but in domains where movement is costly, it becomes inferior to other algorithms, which aim to reduce movement as well.