Intervals on the Guitar

An interval on the guitar measurement is the distance between 2 notes. There are 2 different types of intervals. The melodic interval for a single note and the harmonic interval for chord.

Using the diagram below I will try to explain intervals. The guitar is made up of frets and each fret is 1/2 step. The distance of 2 frets is a whole step. The diagram below is the layout of a typical guitar fret boards first 12 Frets. The E on the top is the first string or the high E. The space between the first  Fret "1" and the second fret "2" is consider a half step, from 1 to 3 is considered a full step. Steps and 1/2 steps are both intervals. Scales are a combination of a root note (That names the scale) a pattern of Whole steps and Half Steps. Chords are a combination of notes in a scale that are measured in steps and half step.

1-E---||--|--|--|--|--|--|--|--|--|--|--|--|
2-B---||--|--|--|--|--|--|--|--|--|--|--|--|
3-G---||--|--|--|--|--|--|--|--|--|--|--|--|
4-D---||--|--|--|--|--|--|--|--|--|--|--|--|
5-A---||--|--|--|--|--|--|--|--|--|--|--|--|

6-E---||--|--|--|--|--|--|--|--|--|--|--|--|
        1   2  3  4  5  6  7  8  9 10 11 12
 

The following is an example of a chord SHAPE. "D Major"
 

1-E---||--|-x|--|--|--|--|--|--|--|--|--|--|
2-B---||--|--|-x|--|--|--|--|--|--|--|--|--|
3-G---||--|-x|--|--|--|--|--|--|--|--|--|--|
4-D---||--|--|--|--|--|--|--|--|--|--|--|--|
5-A---||--|--|--|--|--|--|--|--|--|--|--|--|

6-E---||--|--|--|--|--|--|--|--|--|--|--|--|
        1   2  3  4  5  6  7  8  9 10 11 12

So when someone say to move a not 1/2 a step up, you know to move your fret finger up one fret. Interval are just a measurement of increments of note, and steps are the guitars way of describing the physical reality of an interval.