The modes have different root tones and also different "tenor tones" this means like music in a major key (ionic) has the 5th as dominant all modes have different recitation tones (fifth or sixth). This makes a melody quite different regarding the finalis (final tone) which usually is the root tone and its leading tone.
It was Glarean who added to the already known antic church modes in his Dodecachordon the Ionian and the Aeolian mode which became after Tinctoris the most usual "modes" of today called now Major and minor:
The authentic modes were the odd-numbered modes, 1, 3, 5, 7, and this distinction was extended to the Aeolian and Ionian modes when they were added to the original eight Gregorian modes in 1547 by Glareanus in his Dodecachordon (Powers 2001a). An authentic mode has its final as the lowest note of the scale, though in modes 1, 3, and 7 it may occasionally descend one note further, in which case this added scale degree is called the "subfinal" which, since it lies a whole tone below the final is also the "subtonium" of the mode. The range of mode 5 (Lydian) does not employ a subfinal, and so always maintains the note F as its lower limit (Powers 2001d). These four modes correspond to the modern modal scales starting on D (Dorian), E (Phrygian), F (Ionian = the Gregorian Lydian), and G (Mixolydian). The tenor, or dominant (corresponding to the "reciting tone" of the psalm tones), is a fifth above the final of the scale, with the exception of mode 3 (Phrygian), where it is a sixth above the final. This is because a fifth above the tonic of mode 3 is the "unstable" B♮/B♭.
The picture shows Rockstro's fourteen modes, showing the range, final, cofinal (or dominant), mediant(s), and participant(s) of each, that gives to each mode (authentic or plagal mode) its unique specific character.