The use of the cluster model permits a uniform description of a number of form factors of electric and magnetic, elastic and inelastic (with excitation of lower levels) high-energy electron scattering on many of the lightest nuclei. Analysis of the results shows that in the case of 6Li the clusters are very isolated. Isolation of clusters is reduced with increasing atomic number but remains noticeable for such nuclei as 12C and 16O. When the cluster isolation is considerable the Pauli principle little affects the form factors ( 6Li), but already for 7Li and heavier nuclei inclusion of Pauli principle appears to be important. The results are compared with calculations on the basis of other models (shell model, random phase approximation, Hartree-Fock method) and with experiment. On the assumption that in the state 0 +(7.66 MeV) the nucleus 12C is a linear chain of three α-clusters one can also describe the cross section of inelastic electron scattering with excitation of this level as well as its decay widths with respect to emission of electron-positron pairs ( Γ e ± ) and quadrupole emission (Γ E2).