You’ll often hear musicians speak about “whole steps” or “half steps.” You may even hear them speak about “going up two steps” or “moving it down a step and a half.” What are they talking about?
If you play your A string on the 3rd fret, then move up and play it on the 4th fret, those two notes are a half step apart. A “step” is just a measured change in pitch (just like a step on a flight of stairs is a measured change in altitude). Guitar frets are spaced at half-step intervals, so a half step is the difference in pitch when you play a note on a guitar string, then play that same string one fret higher (or lower). A whole step (which, logically, is two half steps) would be the interval between notes that are two frets apart. Two steps would be a four-fret distance apart, etc, etc.
Here are the 12 notes of Western music:
A A#/Bb B C C#/Db D D#/Eb E F F#/Gb G G#/Ab
Look at the list and figure out how many steps are between different pairs of notes. Keep in mind that each of the notes listed above is a half step away from the note next to it.
Here are some sample distances:
A to C: 1-1/2 steps
C to E: 2 steps
E to F: ½ step
A# to C#: 1-1/2 steps
Bonus note: some musicians call a step a “tone” and a halfstep a “semitone.”