Hey & welcome!

Originally Posted by: ELKAT100

If the string length between the bridge & the nut is the same and you would barre at the first fret or at the nut why do you get different notes if the length is the same.

If I understand your question, the difference is the mass.

Regarding the strings of any musical instrument, the pitch is determined by: length, tension & mass (thickness). So, the lower (or bass strings) are thicker so they have more mass & are lower in pitch. The strings get thinner & have less mass as they get higher. The result is that the strings can be about the same length, but maintain tunings at different pitches.

Hope that helps!