If you skip one note and go to the next note, this is a Tone
See the diagram below
The notes of the A Major Scale are
A B C# D E F# G# A
On the guitar each note (fret) side by side of each other is a Semitone interval.
If you miss one note (fret) and go to the next note (fret) this is then a Tone.
NOTE:- All the blue numbers shown on the guitar neck are the notes of the A Major Scale all over the neck of the guitar. You see there are many positions to play any scale on the guitar. Study the diagram above.