Look here, it's a well-known table of advanced classes. An advanced class or specialization – there's no difference besides the name; both concepts imply that the hero receives a specific bonus to one of the existing skills. However, in Heroes 4, some specializations (or advanced classes) give the hero unique abilities that heroes of no other class have. Perhaps the most striking example is the advanced class of Demonologists.
Look here, it's a well-known table of advanced classes. An advanced class or specialization – there's no difference besides the name; both concepts imply that the hero receives a specific bonus to one of the existing skills. However, in Heroes 4, some specializations (or advanced classes) give the hero unique abilities that heroes of no other class have. Perhaps the most striking example is the advanced class of Demonologists.