What note is played on the E string at the 12th fret?

The note played on the E string at the 12th fret is E. This is because the guitar is tuned to standard tuning, where the open E string serves as the sixth string and is tuned to an E note. Each fret represents a half step in pitch, so at the 12th fret, you have moved up 12 half steps (or one octave) from the open string. Therefore, when you play the E string at the 12th fret, you are effectively playing the same note you started with, which is E, but one octave higher. Understanding the concept of octave placement is crucial for navigating the fretboard effectively and recognizing the relationship between pitches on different strings.