The course aims to present the relationship between the Kronecker invariants of a given matrix pencil $P(s)=SE-A$ and the spectral quantities associated with a pair of linear relations, its range and kernel representations. This relationship is useful for obtaining bounds for the Kronecker invariants of a perturbed matrix pencil $P'(s)=sE'-A'$ in terms of the Kronecker invariants of $P(s)$, translating (finite-rank) perturbation problems among matrix pencils into perturbation problems among linear relations.