The conjecture that almost every graph is determined by its spectrum

Let a graph be determined by its spectrum if every graph with the same adjacency-matrix spectrum is isomorphic to it.

Spectral determination conjecture. Almost every graph is determined by its spectrum.

This is a central question in spectral graph theory concerning how much information the adjacency spectrum encodes about graph structure. The statement is presented as a persisting problem; its resolution is not indicated in the source.