The Natural is an Accidental that removes any kind of Sharp or Flat from a note. A Natural will always be one of the White Keys on the Piano Keyboard.
Chromatic intervals typically involve using accidentals. This chart shows the five kinds of accidentals and what each accidental does. Accidentals make it possible to use notes that are not in the key signature.
The five kinds of accidentals are...
The Natural simply removes any kind of sharp or flat that already applies to the note, such as a sharp or flat in the key signature. When a natural is placed in front of a note, that note will always be one of the white keys on the piano keyboard. Since the natural removes or cancels a sharp or a flat, the natural can raise or lower a note. The natural is the only accidental that can do this.