How can one determine whether an interval is major or minor?

The key difference between a major and minor interval is the number of half steps between the two notes. In a major interval, there are typically two whole steps (or four half steps) between the notes, while in a minor interval, there are typically one and a half steps (or three half steps) between the notes. By counting the number of half steps between the two notes in the interval, one can determine whether it is major or minor.