On this video I demonstrate three kinds of scales:
*Chromatic scales — made of all half steps
*Whole tone scales — made of all whole steps
*Pentatonic scales — a 5-note scale composed of the root, 2nd, 3rd, 5th and 6ths of a major scale.

(On the video I said there are only 2 pentatonic scales: that is not quite accurate. You can have many different 5 note scales but for practical purposes the main two are built on all white keys and all black keys.)

For a complete course on scales please go to All About Scales & How To Use Them

A scale is a series of notes in ordered intervals (distances between notes). The notes of a scale appear (and are thought of) as “steps” (tones). Perhaps the best way to understand scales is to

first understand a major scale (Do, Re, Me, Fa, So, La, Ti, Do). The steps of a major scale are: Beginning note - whole step - whole step - half step - whole step - whole  step - whole step - half

step. In the case of a C major scale, the notes would be: C-D-E-F-G-A-B-C with a half step (semitone) between E and F, and B and C. In the case of a G major scale, the notes would be: G-A-B-C-D-E-

F#-G with a half step between B and C, and F# and G. (Another way to “call out” a G major scale would be to say it’s a major scale beginning with the note G.)

A scale’s name is determined by the notes in the scale and their relationship to each other (and is almost always named by the first note of the scale). For example, a minor scale is different than

a major scale in that there is a half step (one piano key up or down) between the second and third notes of the scale, and a whole step (two piano keys up or down) between the third and fourth

notes (as shown in the paragraph above).

Compare this C minor scale with the C major scale above. The C minor scale: C-D-Eb-F-G-A-B-C (the note E is now Eb, a half step or one key lower). And compare this G minor scale with the G major

scale: G-A-Bb-C-D-E-F#-G (the note B is now Bb, a half step or one key lower). (Another way to “call out” a G minor scale would be to say it’s a minor scale beginning with the note G.)

The term “scale” also refers to the type of scale such as chromatic, whole tone, and diminished scales.

A chromatic scale consists of only half steps (semitones). At the piano, you would play every key in succession (up or down—ascending or descending). Here are the notes of a G chromatic scale: G-

G#-A-A#-B-C-C#-D-D#-E-F-F#-G. (Notice that there are no black keys between the notes B and C and E and F. On the piano, these notes are represented by two white keys being next to each other).

Although a chromatic scale always consists of the same notes in the same order, it is named by the note used to begin the scale.
 
A whole tone scale is a scale where each note is separated from another by a whole step. There are only two whole note scales: C, D, E, F#, G#, A#, C and B, Db, Eb, F, G, A, B. Each contains six

notes and are often called hexatonic scales.

Each tone of a diminished scale is one and a half steps apart.

The term modal refers to scale names such as Lydian, Ionian, and Dorian that tell the musician which notes are in the scale. We’ll define those fully at a different time.

Major scales are ladders of notes that lead from the root note up to the octave note. There are 8 notes in a major scale (7 different note names) and they are always arranged in this pattern:
Whole step, whole step, half step, whole step, whole step, whole step, half step.  Watch this 2-minute video and you’ll see how simple it is to understand: