Let’s start with the F Major scale as an example.
T – W – W – H – W – W – W – H
F – G – A – Bb – C – D – E – F

Each note corresponds to a degree. Number them.
F – I , G – II, A – III, Bb – IV, C – V, D – VI, E – VII, F – VIII

Each degree corresponds with a mode that is named in the list below. Each mode brings a different scale with different sounding intervals.
I – Ionian – 1 – 1 – 1/2 – 1 – 1 – 1 – 1/2 W – W – H – W – W – W – H
II – Dorian – 1 – 1/2 – 1 – 1 – 1 – 1/2 – 1 W – H – W – W – W – H – W
III – Phrygian – 1/2 – 1 – 1 – 1 – 1/2 – 1 – 1 H – W – W – W – H – W – W
IV – Lydian – 1 – 1 – 1 – 1/2 – 1 – 1 – 1/2 W – W – W – H – W – W – H
V – Mixolydian – 1 – 1 – 1/2 – 1 – 1 – 1/2 – 1 W – W – H – W – W – H – W
VI – Aeolian – 1 – 1/2 – 1 – 1 – 1/2 – 1 – 1 W – H – W – W – H – W – W
VII – Locrian – 1/2 – 1 – 1 – 1/2 – 1 – 1 – 1 H – W – W – H – W – W – W

Each mode brings different colors and feelings :
Ionian – Natural major mode. festive, very strong, happy sounding, and the most used scale.

Dorian – Minor mode, very sad, nostalgic, romantic. Perfect for lullabies and love songs.

Phrygian – Typical flamenco mode. Minor yet very dancing.

Lydian – Very harsh major mode, mainly due to the augmented 4th and major 7th. Sounds great for metal songs. A lot of war anthems and military songs are written in this mode.

Mixolydian – Major mode, not as happy or powerful as the Ionian, mainly due to the minor 7th. Wonderful for blues solos.

Aeolian – Regular minor mode. Incredibly versatile, so many things to do with it.

Locrian – Odd sounding minor mode. Nice if you want to corrupt a tender song with a strange melody.

In the key of F the modes would be as follows:
I – Ionian – F, G, A, Bb, C, D, E
II – Dorian – G, A, Bb, C, D, E, F
III – Phrygian – A, Bb, C, D, E, F, G
IV – Lydian – Bb, C, D, E, F, G, A
V – Mixolydian – C, D, E, F, G, A, Bb
VI – Aeolian – D, E, F, G, A, Bb, C
VII – Locrian – E, F, G, A, Bb, C, D