Explore the concept of profinite rigidity in 3-manifold groups through this one-hour lecture by Martin Bridson. Delve into the unique determination of certain 3-manifold groups among finitely generated, residually finite groups based on their finite images. Discover the reasoning behind this phenomenon and examine numerous examples of such groups. Investigate groups that exhibit profinite rigidity among finitely presented groups but not among finitely generated groups. Learn about the connections between profinite rigidity, triangle groups, and Seifert fibred spaces in this advanced mathematical discussion, part of the Workshop on Groups around 3-Manifolds held at the Centre de recherches mathématiques.