To subtract the fractions \( \frac{5}{6} - \frac{3}{8} \), we first need to find a common denominator. The least common multiple (LCM) of 6 and 8 is 24.
Next, we convert each fraction to have a denominator of 24:
\[ \frac{5}{6} = \frac{5 \times 4}{6 \times 4} = \frac{20}{24} \]
\[ \frac{3}{8} = \frac{3 \times 3}{8 \times 3} = \frac{9}{24} \]
Now we can subtract the two fractions:
\[ \frac{20}{24} - \frac{9}{24} = \frac{20 - 9}{24} = \frac{11}{24} \]
Thus, the answer in the most simplified form is:
\(\frac{11}{24}\)