MI: LIBRARY: THEORY: BASICS: HALF/WHOLE STEPS

In most music, the smallest interval, or distance, between two tones is a half step.  Two half steps combined make a whole step.  Take a look at the piano keyboard, notice a black key between C and D.  The distance from C up to that black key is a half step.  From the black key to D is a second half step.  The two half steps combined equal a whole step.  The nearest key, black or white, above or below any other key is a half step.   So, the next white key above B or E, or below C or F, is a half step.