The description of F₂ at low Q²

We analyse the data for the proton structure function F₂ over the entire Q² domain, including especially low Q², in terms of perturbative and non-perturbative QCD contributions. The small distance configurations are given by perturbative QCD, while the large distance contributions are given by the vector dominance model and, for the higher mass qq̄ states, by the additive quark approach. The interference between states of different qq̄ mass (in the perturbative contribution) is found to play a crucial role in obtaining an excellent description of the data throughout the whole Q² region, including photoproduction.