How do homologues differ from isomers, or isomers from homologues, in short, are their differences stupid?

Homologues are compounds belonging to the same class and differing by one (or more) CH2 methylene group. Example: the closest homologues of ethanol C2H5OH are propanol C3H7OH, butanol C4H9OH);
Isomers are compounds that have the same composition, but different structures, or belong to different classes. Example: butanol C4H9OH is an isomer of diethyl ether;