En Microsoft Excel, las letras de la columna son las etiquetas utilizadas para identificar cada columna en una hoja de cálculo. They start with "A" for the first column, "B" for the second, and so on, continuing through the alphabet and then using combinations of letters (AA, AB, AC... AZ, BA, BB, etc.) for columns beyond Z. They are essentially the horizontal coordinates of a cell, paired with the row number (1, 2, 3...) to form a unique cell address (e.g., A1, B5, AA10).
