The 7 modern modes can be generated from a major scale by choosing each note as the start, each mode can be numbered by the note of the major scale on which it starts, e.g. using the white notes of the piano: (1) C Major, (2) D Dorian, (3) E Phrygian, (4) F Lydian, (5) G Mixolydian, (6) A Aeolian, (7) B Locrian.
Alternatively the modes all starting on the same note can be related by single note changes as shown below, follow the heavy arrows.
Many other scales can be generated by single note changes, for example, Freygish and Misheberakh, which have larger intervals (augmented 2nds), are common modes in Klezmer music, but they also appear (with different names) in many other musical traditions.
T = tone, S = semitone = A, augmented 2nd.
For a PDF version, of simpler version of this diagram, see here