The expression "\frac12" represents a fraction, which is a way to show a part of a whole. In this case, the number 1 is the numerator, indicating how many parts we have, while the number 2 is the denominator, showing how many equal parts the whole is divided into. Thus, \frac12 means one part out of two equal parts. Fractions like \frac12 are commonly used in everyday situations, such as cooking or measuring. For example, if a recipe calls for \frac12 cup of sugar, it means you need to use one half of a cup to achieve the desired sweetness in your dish.