In music, a step, or conjunct motion, is the difference in pitch between two consecutive notes of a musical scale. In other words, it is the interval between two consecutive scale degrees. Any larger interval is called a skip (also called a leap), or disjunct motion.

In the diatonic scale, a step is either a minor second (sometimes also called half step) or a major second (sometimes also called whole step), with all intervals of a minor third or larger being skips. For example, C to D (major second) is a step, whereas C to E (major third) is a skip.

More generally, a step is a smaller or narrower interval in a musical line, and a skip is a wider or larger interval with the categorization of intervals into steps and skips is determined by the tuning system and the pitch space used.

Melodic motion in which the interval between any two consecutive pitches is no more than a step, or, less strictly, where skips are rare, is called stepwise or conjunct melodic motion, as opposed to skipwise or disjunct melodic motion, characterized by frequent skips.

Source: Steps and skips – Wikipedia