This will be an introductory talk on cellular sheaves: a type of
algebraic data structure that is surprisingly useful of late in
topological data analysis. The talk will be example-driven, with
a number of recent results surveyed in joint work with some
of my current students, including Jakob Hansen and Hans
Riess. There will be something for everyone, as the subject
and its applications involves the cohomology of sheaves,
the geometry and dynamics of Laplacians, and the combinatorics
of graphs and lattices.