\"{a}The \"{a} command in LaTeX is used to place an umlaut (two dots) over the letter 'a', which is common in languages like German. This is part of the accent functions that can be used inside text mode to modify the appearance of characters.
The word 'Äpfel' (apples in German) with an umlaut over 'A'.
\"{a}pfelThe word 'schön' (beautiful in German) with an umlaut over 'o'.
sch\"{o}nThe word 'früh' (early in German) with an umlaut over 'u'.
fr\"{u}h