ELI5, why are the musical notes represented by letters in some places (C-D-E-F-G-A-B), but in others by their sound (do-re-mi-fa-sol-la-si-do) ?

Question

I’m from Mexico and the way I learned the musical notes was by their sound, however some friends from other places learned the notes with letters.

In: Other

Answer 1

Do-re-me and such are used to show a notes position in a scale, for example in a C major scale, C is do, D is re. A B C and so-on are the exact note names, corresponding to a specific pitch