As explained by Jason Davies, Lloyd’s relaxation algorithm (named after Stuart P. Lloyd) generates a centroidal Voronoi tessellation, which is where the seed point for each Voronoi region is also its centroid.

The algorithm computes the Voronoi diagram for a set of points, moves each point towards the centroid of its Voronoi region, and repeats.

Important concepts:

• Convergence - every point that is being "relaxed" is moving towards the center point of a Voronoi cell, but due to computational limits in numerical precision it may not ever perfectly reach it. Therefore it is a good idea to use some sort of preset distance threshold value that causes points to stop moving once they are close enough to their target point.

Articles:

• Lloyd's algorithm on Wikipedia
• Voronoi relaxation (Lloyd's algorithm) in Processing by Alberto Giachino

Code projects:

• Javascript implementation of Steven Fortune's algorithm to compute Voronoi diagrams - Demo 5: Lloyd's relaxation by Raymond Hill (JavaScript) (source repo)
• Lloyd's Algorithm by Mike Bostock on Observable (JavaScript and D3.js)
• Lloyd's Relaxation by Luca Sbardella (JavaScript and D3.js)
• Lloyd's Relaxation by Jason Davies (JavaScript, see DOM for source code)